Are the only things that can be "known" material things? All else we believe is by "faith"? Can the supernatural be known?
Comments
If there are (in the metaphysically serious sense of ‘are’) numbers, laws of logic, propositions, relations, sets, etc., then it seems like we do have knowledge of immaterial things. That, however, isn’t obviously inconsistent with naturalism, understood as the thesis that there are no causally efficacious non-physical entities, or even just the thesis that .
I was glad to hear Koukl bring up Descartes. Unfortunately, I didn’t completely follow Koukl’s argument from knowledge of the self. It may have the same problems as one of Descartes’ arguments. Here’s one of the ways Descartes argued:
(1) Everything that is physical has the property being the sort of thing whose existence I can doubt.
(2) My self lacks the property being the sort of thing whose existence I can doubt.
(3) If a and b do not share exactly the same properties, then a is not identical with b.
(4) Therefore, my self is not identical with anything physical.
The problem is that being the sort of thing whose existence I can doubt is a predicate that does not express a genuine property. Suppose that it did. Then it would stand to reason that the following argument would be sound:
(a) Superman has the property of being loved by Lois.
(b) Clark Kent lacks the property of being loved by Lois.
(c) If a and b do not share exactly the same properties, then a is not identical with b.
(d) Therefore, Superman is not identical with Clark Kent.
Oops, looks like the last sentence of my first paragraph got cut off. Here's what it was supposed to say:
That, however, isn’t obviously inconsistent with naturalism, understood as the thesis that there are no causally efficacious non-physical entities, or even just the thesis that the entirety of the mental world depends for its existence on the physical world.
So we have a thinker. At this point that's just something that thinks - whatever thinking is. We still know little to nothing about thinking or thinkers. In particular, it remains to be seen if the thinker the one Descartes is used to thinking of as Descartes. So he can't say "I think therefore I am." The I is the one he is used to thinking of as Descartes. He got that idea from living in the world. If he imports it, he's begging the question.
Try to imagine Descartes doing his thing without importing assumptions from his life in the world. Imagine Descartes is a brain in a vat without sensations or memories of the outside world. Where is he even going to get the idea of an immaterial self if you don't preload him with it?
What can you preload him with without begging the question?
RonH
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Malebranche,
...the mental world depends for its existence on the physical world.
"The mind is what the brain does." - Steven Pinker
I think Greg was trying to argue against the traditional view of naturalism, not the more recent view that often includes spiritual an immaterial notions. For many, today's naturalism looks a lot like new-age mysticism, pantheism or Buddhism.
For many, today's naturalism looks a lot like new-age mysticism, pantheism or Buddhism.
I don't know who you have in mind, but my impression is that most naturalists would say that they simple endorse one of the following (none of which entails mysticism, pantheism, or Buddhism of any sort):
(a) Only those entities required by our best physics exist (so, on this view, numbers exist)
(b) There are no causally efficacious non-physical things.
(c) The entire mental world depends for its existence on the physical world.
Each of these characterizations is compatible with Platonism about abstract objects, and none of these characterizations entails anything of the sort you suggested.
(a) Only those entities required by our best physics exist (so, on this view, numbers exist)
I think you have woven the argument too tightly around the empiricism. First, our rational minds perceive the reality of numbers. Second, we use numbers in physics and elsewhere to help us understand reality.
(b) There are no causally efficacious non-physical things.
Desire (or will) isn't causally efficacious? What reasons do you have for thinking this is true?
(c) The entire mental world depends for its existence on the physical world.
I have no reason to think this is true at all. I do have reasons to think the opposite is true.
Logic is part of the mental world. We perceive it to be immutable, and dependent on nothing (no thing).
I see no reason to think that logic can fail to exist or can be altered as a result of the physical world being altered.
First, an entirely adequate definition of naturalism defines it as the view that the entire mental world ultimately depends for its existence on the physical world. This is plainly inconsistent with theism, since according to theism the entire physical world ultimately depends for its existence on God, a mental substance.
Second, naturalism as defined in no way obviously entails that the laws of logic depend for their existence on physical things. Some naturalists (perhaps the early Russell) believe that abstract objects, such as numbers, universals, propositions, etc., are neither mental things nor physical things, but constitute a third kind of entity. The naturalist might maintain that there are at least three distinct kinds of entities: (i) physical things, (ii) mental things, (iii) and Platonic abstracta. They might even think that though it is contingent that physical and mental things exist, Platonic abstracta exist necessarily. I see no incompatibility between this view and naturalism as defined above. You assume (very controversially) that everything that exists is either physical or mental. That, however, is rejected by many philosophers, since Platonic abstracta are thought of by many to be a distinct kind of thing entirely.
Third, I don’t need to be a naturalist of any sort to make these points. I am not a naturalist. I think it is necessarily false. Nevertheless, I am still able to comment on entailment relations between naturalism and other propositions (such as ‘pantheism is true’ or whatever).
Fourth, since naturalism as defined does not entail that there are no numbers, it is no good to object to naturalism (as J.P. Moreland tries to do) by citing the existence of numbers.
Finally, you ask if desire (which I understand to be a mental state) is causally efficacious. I don’t know. But I can tell you what a naturalist could say. Some naturalists might say that mental states are identical with physical states, and physical states are causally efficacious. So, they would say, “Yes, desires are causally efficacious, but that’s only because they are physical.” Epiphenomenalists, on the other hand, will grant that desires are non-physical, but they simply deny that they are causally efficacious. Only physical states are causally efficacious. I gather that you disagree with these folks. I probably do too. But disagreement is easy. Refutation is what is so incredibly difficult.
....naturalism defines it as the view that the entire mental world ultimately depends for its existence on the physical world.
I would agree. It's described as a "bottom up" worldview. The problem with the Platonic abstracta of naturalism is that they require grounding. For example, a naturalistic "ought" requires grounding in a transcendent, necessary and immutable source. That makes either the Platonic abstracta, the mental, the physical or some unknown to be the grounding source = the rock bottom of the "bottom up" worldview.
However, nothing in a naturalistic worldview is transcendent, necessary or immutable because nature has not given us any reason to think that it has any such qualities. It's a mere logical possibility built upon nothing more. In other words, pure speculation without reasons for advancing the speculation.
No need to argue for 'it being true.' We know the natural world exists. The question is whether anything exists outside it and the burden is on the one who says something does.
The question is whether anything exists outside it and the burden is on the one who says something does.
I disagree, slightly. I think anyone who presents a perspective has a burden. These perspectives could be for the existence of something, for the non-existence of something, for our ability to know about the existence of something beyond, for the meaningfulness of talking about that beyond, and so on. I think merely pinning the burden upon the one who claims something exists beyond is too simplistic.
If we're, in the general sense, going to have a discussion, then all involved parties must be prepared to present and support their perspectives.
Malebranche, I'm going to change the argument you presented above a little bit in order to make it easier for me to make my point. If I make a false move, I trust you to point it out.
For starters, I am going to treat Leibniz's Law
If a and b do not share exactly the same properties, then a is not identical with b
as a rule of inference rather than a premise in the argument
Your claim seems to be that an argument like the one below is a simple intensional fallacy:
(1) I can doubt the existence of any physical thing any time I consider it.
(2) I cannot doubt the existence of my self any time I consider it.
(3) Therefore, I am not identical with any physical being (by 1, 2 and Leibniz's Law).
The problem is that properties based on mental attitudes, like believing that P is true or doubting that P is true or loving X, usually do not obey Leibniz's Law.
You present another argument to exemplify this point:
(a) Lois Lane loves Superman.
(b) Lois Lane does not love Clark Kent.
(c) Therefore, Superman is not identical with Clark Kent (by a, b and Leibniz's Law).
This argument is manifestly invalid. The fact that it has true premises and a false conclusion is a dead giveaway of its invalidity. The underlying reason for its invalidity is that the 'property' of being-loved-by-Lois is not a real property subject to Leibniz's Law.
But there is an important difference between the terms involved in 1-3 and the terms involved in a-c. There are modal elements in the predicate terms that may well render them subject to Leibniz's law.
Adapting the Lois/Superman/Clark argument to make it better match 1-3, it would look more like this:
(A) Lois Lane can refrain from loving Clark Kent at any time she looks at him.
(B) Lois Lane cannot refrain from loving Superman at any time she looks at him.
(C) Therefore, Superman is not identical with Clark Kent (by A, B and Leibniz's Law).
This argument is unsound of course, but that is both A and B, turn out to be false. Lois does love Superman, but not in the way that A and B describe.
But argument A-C is not obviously invalid in the way that a-c is. Look at it this way. Suppose that Lois really did find that she couldn't fail to love Superman every time she looked at him. Doesn't that imply some interesting connection between those two individuals or, at least, between Lois and Superman's type of being? The mere sight of him (or a being of his type) is followed by irresistible love. Wouldn't that connection give her the power to identify Clark Kent as Superman, or at least as the Superman kind of being, because she would find herself compelled to love him whenever she looked at him? It looks to me like it would (finally, a super-power for Lois!)
Thanks for your comment. I don't see where we disagree.
Here's a perspective:
Koukl concludes he exists because he's thinking; he couldn't be thinking if he didn't exist. Fine.
Then, he says he believes he 'also' has a physical body. But, he says, since his senses can deceive him he could be mistaken about this.
STOP!
Why does he need this also?
All he has concluded from his thinking is that he exists. He hasn't established an immaterial component to his existance. He concluded his existance without using his senses but that doesn't mean he has an immaterial component that would require the 'also' when he refers to his physical component.
The means by which he established his existence - I think therefore I am - does not imply this existence has an immaterial component. It works just as well for a purely material existence. The possibility that his senses could deceive him into believing he had a material existence doesn't change one iota.
So his argument fails. It all comes to a head around 4:25.
There. I gave a 'perspective': that Koukl's case for an immaterial mind fails. So it's my burden to say why and I did so. I think that satisfies my burden in that regard.
It should go without saying that my refuting Koukl's particular argument is not the same as my claiming there is no immaterial mind.
It might be that I believe there is no immaterial mind. But I didn't assert it so I'm not obligated to defend it. All I'm obligated to defend is my rejection of his particular argument.
It might be that I have no supernatural beliefs. Am I therefore obligated to defend the statement: the natural world is all there is?
"Try to imagine Descartes doing his thing without importing assumptions from his life in the world. Imagine Descartes is a brain in a vat without sensations or memories of the outside world. Where is he even going to get the idea of an immaterial self if you don't preload him with it?"
Since Descartes did, essentially, assume just what you've supposed is a knock-out punch. The case you ask us to imagine is not difficult at all.
Descartes claims to be unable to doubt in his own existence even if God is evil and bending all His power on deceiving Descartes (which is a far more troublesome assumption that your brain in the vat). Descartes does not have this inability when it comes to the physical world. That's why he thinks that mind and matter are distinct.
Yes, but I think we are all missing one key point that Greg is making in his video. The point is that we have to have the ability to reason and think logically before we can observe and talk about the natural world around us. On that point, strict forms of naturalism fail because the claims are self defeating.
As far as I know, Descartes assumed that if he detected a thinker then the thinker had to be him.
Kierkegaard called Descartes out on this but I got it a long time ago from my friend Al who seemed to have got it on his own but for all I know now got it from Kierkegaard.
I assume Descartes imported this assumption from his life in the world. Maybe I'm wrong there but I can't think where else he might have gotten it.
I doubt that Descartes made his best efforts on this - he had certain conclusions he wanted to get to and wouldn't want to shut the project down at the outset.
Descartes does not have [the inability to doubt in his own existence] when it comes to the physical world. That's why he thinks that mind and matter are distinct.
Here are the exact same mistakes repeated by Koukl.
1) I think, therefore I am doesn't distinguish between a material I and a non-material I. It is entirely agnostic on the subject.
2) We certainly have sensory evidence for the material body. Sweeping this evidence off the table is the worst thing you can do with it. To claim you can go farther is to invent evidence contrary to what you have. If you do sweep the sensory evidence for the material body off the table then all you have is the I think, therefore I am which is still agnostic on the material/immaterial question.
I have the feeling I've encountered a named fallacy that covers this.
I think RonH is right in that the cogito ergo sum does not, in and of itself, prove immateriality.
Koukl did not present it as such a proof. He presented it as the proof of actual knowledge and of proof of non-sensory knowledge (the primary (only?) way of knowing the material world).
He then presumes the immateriality of the self.
But this presumption he can also demonstrate to be true, although he has not presented the argument here, in this argument for knowledge.
The question is whether anything exists outside it and the burden is on the one who says something does.
There are reasons, currently under debate, for thinking something like that does exist. I've given one reason, but there are more. Of course, nothing has been proven in the scientific sense, and likely won't ever, but the burden is no longer exclusively on our shoulders. If you disagree with the reason(s) presented, it it your burden to give a reason-based rejoinder that goes beyond speculation or mere logical possibility.
Previously I said:
...nothing in a naturalistic worldview is transcendent, necessary or immutable because nature has not given us any reason to think that it has any such qualities. It's a mere logical possibility built upon nothing more.
What reasons do you have for thinking nature has "informed us" that it has these qualities such that logic can be considered necessary and immutable?
"Descartes assumed that if he detected a thinker then the thinker had to be him."
This critique is a joke. I say this with some trepidation because it does actually appear to be Kierkegaard's and I hate to say such things about the arguments of geniuses (which Kierkegaard certainly was).
Let's spell it out further. The claim is that Descartes is involved in this argument:
1) "x" thinks
2) I am that "x"
Therefore:
3) I think
Therefore:
4) I am
Descartes is wrong, according to this critique, because premise 2 begs the question.
Here is the problem:
This is not Descartes' argument.
Descartes' argument is this:
1') I think.
Therefore:
2') I am.
Notice that the move from line 1' to line 2' in the actual Cartesian argument is exactly the same as the move from line 3 to line 4 in the critique's reconstruction.
What that means is that critique grants that the Cogito argument is logically valid. What is at issue is whether Descartes' Premise "I think" is true and knowable.
The critique of Descartes assumes that Descartes believes that he thinks because he first believes that something thinks and then assumes (without justification presumably) that he is that thing.
Anyone who reads Descartes for more than five minutes without simply trying to dismiss him will realize that this is not the way he argued. His point was that any effort to deny the premise was self-defeating. And just a few minutes reflection on that will show that he was absolutely right about that.
Let's try to deny Descartes' premise:
Effort 1: I hereby boldly deny that I think!
Oh...wait. I had to be bold. I had to understand a claim. I had to assert that claim is false. But every one of those actions is a type of thinking on my part.
Effort 2: I deny that I think.
No...I still had to think to do that.
Effort 3:
I doubt that I think?
Nope...sorry, my doubts are among my thoughts.
So Descartes' reasons for believing that He thinks have nothing to do with some prior observation of thought that he makes coupled with the identification of himself with the thinker. They have everything to do with the self-defeating character of making the claim that one is not thinking.
BTW, Descartes may well be committed to this argument (and the argument is sound in any case:
1) I think
Therefore:
2) I exist
Therefore:
3) There exists at least one thing that thinks.
That is, Descartes' cogito proves the existence of the mental.
So the issue has never been whether matter-independent mental substances exist. As if matter were somehow a given and we have to decide whether there's something else and whether mind is that something else.
What's a given is mind. The issue is whether any mind independent material substances exist.
I've certainly never seen a good or challenging argument to suggest that they do. (Descartes own efforts on this front fall short).
I don’t think the modal points do much work to help the argument.
To illustrate, suppose that God made some rational creature and equipped the creature with cognitive faculties such that the creature could not doubt that water exists but could doubt that H2O exists. Call the creature Aqua. We now may develop the following argument:
(P1): Water has the property being such that its existence cannot be doubted by Aqua.
(P2): H2O lacks the property being such that its existence cannot be doubted by Aqua.
(P3) If a and b do not share exactly the same properties, then a is not identical with b.
(C4) Therefore, water is not identical with H2O.
This argument is bad and seems to be a parity of the Cartesian argument rehearsed by Koukl.
"Why can Descartes excuse himself from asking Is the thinker me? by simply saying That's not the way I argue?"
For the same reason that any arguer can excuse themselves of defending an argument that they do not advance...they do not advance it.
Descartes has different reasons for thinking that his first premise is true than those presupposed by the critique's reconstruction. He is under no obligation to defend his first premise as the critique proposes.
All parties agree that his argument is valid. So that, as they say, is that.
"Why does argument fail to establish the existence of matter? Do you doubt matter exists? If not, why mention this failure of argument?"
What no argument I've seen has been able to establish is the existence of mind-independent matter. Indeed, I haven't seen an argument to show that the idea of mind-independent matter has any coherent content. So I have serious reservations about whether the stuff is even possible, let alone actual.
But I'll grant you all the mind-dependent matter you like.
The inability in question is not a simple limitation in cognitive faculties. In the argument for the distinction between mind and matter, the inability in question is a logical inability. Every effort to doubt my own existence provides, as its logical consequence, proof of my existence. This is not the case with every effort to doubt the existence of, for example, my brain.
This wrinkle is not something that I think can be easily captured in the Lois and Clark or the Aqua examples. For the sake of argument, I'm willing to grant that Lois and Clark, even my version, is more like the Aqua case than it is like mind and matter case and may be problematic in the same way.
(I should note that I do not think that water is identical to H20...H20 is a useful predictive model for water. But it is no more water than a Newtonian description of a wheel is a wheel...so I'm not sure that Aqua is a cogent counterexample.)
I see your point better now and apologize for making you repeat it.
However, I still think Descartes has some more duties. There have to be experiences carried into the exercise in order for him to answer himself: What do you mean by I? What to you mean by think?, and finally, ala Bill Clinton What do you mean by am? It takes a lot to answer these questions. Descartes needs to have definitions of I, think, and be at hand but he is also supposed to be in a state of radical doubt.
I just realized something else. You say Descartes is justified I think. cannot be denied. I have just received an mass email from Koukl that says:
Given any point of view (e.g., “God exists”), there are only three possible responses to it. You can affirm it (“God does exist”), you can deny it (“God does not exist”), or you can withhold judgment (“I don’t know”), either for lack of information or lack of interest.
What did Descartes do about the option of withholding judgement for lack of information?
Koukl says "I can be more confident of my knowledge about something that is supranatural than something that is in the natural world" at 4:32.
That statement is based on the congnito ergo sum and it seems to be a conclusion: we can know immaterial things.
Something in that statement is based upon the cogito, but it is not the immateriality.
I was going to say that the cogito does not demonstrate immateriality, and that probably Decartes knew it (since he wasn't arguing that) and probably Koukl knows it as well (but as you will see, as I continued to type I rethought that conclusion).
What is concluded from the argument is that something can be known (Descartes), and
there are ways to know that are not derived via the senses (ie, the way material things are perceived) (Koukl). He gives the next example when he says how we know that the laws of logic are known.
Koukl himself refers to another method of acquiring knowledge about the self, and that is the sensory perception of the physicality of the self. But the senses can be fooled (in the extreme this lead to the skeptical position against which Descartes was arguing), so we have no confidence that the physical aspect of the self exists. Yet we do know and have perfect confidence that the self exists. So it may or may not be physical, but we have no confidence in the argument for its physicality, or materiality.
On the other hand, upon further reflection, it actually does give more confidence in the supranatural than in the "natural" as we know there is a self but do not know that it is extended in space. Therefore we can doubt that it is extended in space. Therefore it might not be. But it is not the case that it might not exist. So the skeptic, he who doubts the conclusions of the senses, in fact, must (almost) admit it is immaterial - because we know it exists and don't know the physical does.
With no confidence the physical exists but absolute confidence I exist, I am left, even without the further arguments for the immateriality of the self, confident that I have an immaterial aspect. And that I know it.
Descartes does, of course, have meanings in mind (pardon the pun) for all the terms you mention. And I imagine they're the standard ones. But even though he's in a state of radical doubt, he still finds that it is self-defeating to doubt "I think" and "I exist", however laden with prior experience and theory the terms involved might be.
What Descartes is moving toward is the idea that there are some things that we can be certain of, in spite of the evil genius, at least so long as we attend to them, and without the need of argument. He allows that we may have used all sorts of arguments and experiences in the past to get us the point that we are now able to see, without reference to argument or experience, that we are unable to doubt them. "I think" and "I exist" are two examples of such things, but so is "7+5=12". It's worth noting that Descartes never says "I think; therefore, I am" in the Meditations (the cogito argument comes from the earlier Discourse on Method). By the time we get to the Meditations, Descartes has realized that the key insight is that he could not deny "I think" to be true, even under radical doubt.
On your second point about withholding judgement, Descartes also had a lot to say. He argued that all the sin and error that humans are responsible for comes from the fact that they do not withhold judgement when they lack adequate reason. Obviously, he must have believed that "I think" was one of the things he had adequate reason for. What is his reason? Simply the fact that any effort to deny, or even to withhold judgement on the claim proves that the claim is true. Withholding ones's judgement is, after all, also a case of thinking.
Now, clearly there is also the possibility of simply not making or withholding a judgement about the "I think". I do this all the time, for example, when I am sleeping or watching television. I am neither making nor withholding judgment about the "I think". When I am watching television, you might be able to argue that I am not thinking at all ;-) But Descartes' point was only to apply to the case where I am actually attending to the proposition "I think". So, though my mind might have winked out of existence during reruns of "Walker, Texas Ranger", whenever I snap out of it and attend to the proposition "I think", I find that the only thing I can coherently do is to affirm it.
Cogito, Ergo Sum: Necessarily, if I am doubting my existence, then I exist.
You go on to note that the following is false:
Cogito, Ergo Corpus: Necessarily, if I am doubting the existence of my body, then my body exists.
But what I am failing to see is how the truth of Cogito Ergo Sum and the falsity of Cogito Ergo Corpus shows that the mind is not physical. The predicate being such that, necessarily, I cannot doubt its existence seems to be no more genuine a property than the property being loved by Lois.
Anyway, I’m not seeing the argument. Perhaps you could outline it clearly.
"Our senses give us a very high degree of confidence that we exist and, specifically, that we have a physical side."
How so? Our senses provide us with mental images. This is evidence that we have a mental side. I'm not seeing any evidence at all for matter (mind independent matter mind you).
Specifically, my senses give me confidence that I exist because there must be an I that is doing the sensing.
Because I am trapped in the sensing agent I don't have a high confidence that the senses are sensing a material external world .... unless I believe in God, of course.
I guess the point is that the cogito proves that thinking things exist. So there is something mental in the world.
What I don't know is whether there is anything physical in the world. Or whether the idea of the physical is even coherent.
I also, for example, don't know whether there is anything schmysical in the world. With that said, suppose that I have no proof that minds (which I know to exist) are not also schmysical. Am I somehow obligated to show that minds are not schmysical?
Our senses give us a very high degree of confidence that we exist and, specifically, that we have a physical side.
There is no corresponding thing that gives us a corresponding confidence specific to an immaterial side.
Parsimony suggests we doubt an immaterial side.
As WL has already pointed out, everything we know about reality comes to us in the form of mental perceptions. You can doubt the extra-mental world, but you cannot doubt the mental world. The moment you doubt it, you confirm it.
You can dream up scenarios where all of your mental perceptions are wrong (brain-in-vat), however that means your perception of the extra-mental world is also wrong.
I guess the point is that the cogito proves that thinking things exist. So there is something mental in the world.
It is important to see that these remarks constitute no reason whatsoever to think there are non-physical entities. At best all we can get from these remarks is the following argument:
(1) If I am thinking, then something that thinks exists.
(2) I am thinking.
(3) Therefore, something that thinks exists.
Notice that I asked you to argue for the truth of the proposition Some non-physical entity exists. Notice furthermore that there is a massive gulf between Something that thinks exists and Some non-physical entity exists. To bridge the gulf you need the following principle:
Mentalism Principle: if something that thinks exists, then some non-physical entity exists.
But now the question becomes, “Why accept the Mentalism Principle?” Without independent support for the Mentalism Principle, you have given no reason to believe that Some non-physical entity exists. Why think that no purely physical object can think? That cannot just be asserted against those who don’t believe it. It must be argued for. So what true premises do you have that validly deliver the Mentalism Principle?
If you are confident that "something that thinks, exists" and you are confident that this knowledge didn't come to you via the 5 senses (which is true), then what are the other options available for you to become aware of its presence? I don't know of any.
"(a) Only those entities required by our best physics exist (so, on this view, numbers exist)
(b) There are no causally efficacious non-physical things.
(c) The entire mental world depends for its existence on the physical world."
(a) and (b) entail (c). There's nothing physical in that relationship. It may be that the mental world depends on the physical world, but the existence of logical relationships means that it is not the case that there are no causally-efficacious non-physical things. (Triple negatives scare me, by the way).
Here's another example. Suppose I choose not to kill my neighbor because I become convinced that it is wrong to kill the innocent because human beings have intrinsic dignity. Several things are going on here. First, the basis for my new moral outlook has no physical referent, intrinsic dignity. Second, my mental change, from potential killer to repentant sinner, is the consequence of my accepting a new belief. Here, the entire cognitive act--the reading, the understanding, the reflecting, the agency, and the believing--and the belief on which this act focused are causally efficacious in changing my character (or putting me on the path to true virtue).
Sure, one can physical components in this narrative. But it is clear that my change in belief and disposition is not the proper subject of physics.
the existence of logical relationships means that it is not the case that there are no causally-efficacious non-physical things.
I see no reason to believe this and good reason to think otherwise. Entailment, after all, is not a causal relationship. All men being mortal and Socrates being a man does not cause Socrates to be mortal. That is just a confusion. I agree with you that if entailment were causal, it would be a good candidate for a non-physical entity with causal power. But the entailment relation is plainly not causal.
Malebranche,
Entailment is causally-efficacious according to the nature of reason. It is a mental "ought". Entailment is a characteristic of reason such that without it, reason would not be reason and would fail to exist.
For those that say it, it makes no sense to say that mental states are identical to brain states because reason and entailment would be a physical thing. What physical thing could could have the quality of "oughtness"? None.
If you agree claims about there existing nothing outside of the natural world must also carry a burden, then we agree. I simply don't think the original statement clearly communicate the idea, and seem to provide a lop-sided perspective.
It's curious that you are emphasizing the claim that there are no causally efficacious non-physical things. As I'm sure you know, the real Nicolas Malebranche put forward a doctrine called occasionalism. Occasionalism held that there are no causally efficacious things, period. Except for God...who is non-physical.
While I don't buy into Malebranche's occasionalism I do think it has this to recommend it: it is virtually impossible to see how there could be any causal interaction between matter-independent mental substances and mind-independent material substances.
(Of course, I tend to deny that there are any mind-independent material substances...so that's my explanation of the impossibility)
You're right. Malebranche defended the claim that x has causal power only if x is identical with God. Pretty interesting, in my opinion.
As far as historical figures go, however, I think that neither Descartes, Malebranche, or Spinoza held a candle to Leibniz, who argued persuasively that Something is a substance only if it has genuine irreducible causal power (which, by the way, is the reason why, strictly speaking, there are no chairs, computers, books, or artifacts of any kind). Given the truth of that conditional, it would follow from occasionalism that there is exactly one substance, which just is the pernicious doctrine of Spinozism. And that, as a matter of fact, is exactly what Leibniz thought of occasionalism (that occasionalism is simply Spinozism in sheep's clothing).
But Leibniz too was an idealist, so, strictly speaking, he also thought that only non-physical immaterial substances have causal power. With Leibniz, Malebranche, and Descartes, I agree naturalism is false,since there are non-physical causally efficacious substances.
If there are (in the metaphysically serious sense of ‘are’) numbers, laws of logic, propositions, relations, sets, etc., then it seems like we do have knowledge of immaterial things. That, however, isn’t obviously inconsistent with naturalism, understood as the thesis that there are no causally efficacious non-physical entities, or even just the thesis that .
I was glad to hear Koukl bring up Descartes. Unfortunately, I didn’t completely follow Koukl’s argument from knowledge of the self. It may have the same problems as one of Descartes’ arguments. Here’s one of the ways Descartes argued:
(1) Everything that is physical has the property being the sort of thing whose existence I can doubt.
(2) My self lacks the property being the sort of thing whose existence I can doubt.
(3) If a and b do not share exactly the same properties, then a is not identical with b.
(4) Therefore, my self is not identical with anything physical.
The problem is that being the sort of thing whose existence I can doubt is a predicate that does not express a genuine property. Suppose that it did. Then it would stand to reason that the following argument would be sound:
(a) Superman has the property of being loved by Lois.
(b) Clark Kent lacks the property of being loved by Lois.
(c) If a and b do not share exactly the same properties, then a is not identical with b.
(d) Therefore, Superman is not identical with Clark Kent.
But this argument is not sound.
Posted by: Malebranche | May 31, 2010 at 06:06 AM
Oops, looks like the last sentence of my first paragraph got cut off. Here's what it was supposed to say:
That, however, isn’t obviously inconsistent with naturalism, understood as the thesis that there are no causally efficacious non-physical entities, or even just the thesis that the entirety of the mental world depends for its existence on the physical world.
Posted by: Malebranche | May 31, 2010 at 06:16 AM
More conservatively Descartes might have said:
So we have a thinker. At this point that's just something that thinks - whatever thinking is. We still know little to nothing about thinking or thinkers. In particular, it remains to be seen if the thinker the one Descartes is used to thinking of as Descartes. So he can't say "I think therefore I am." The I is the one he is used to thinking of as Descartes. He got that idea from living in the world. If he imports it, he's begging the question.
Try to imagine Descartes doing his thing without importing assumptions from his life in the world. Imagine Descartes is a brain in a vat without sensations or memories of the outside world. Where is he even going to get the idea of an immaterial self if you don't preload him with it?
What can you preload him with without begging the question?
RonH
------------------------------------
Malebranche,
"The mind is what the brain does." - Steven Pinker
Posted by: RonH | May 31, 2010 at 09:40 AM
I think Greg was trying to argue against the traditional view of naturalism, not the more recent view that often includes spiritual an immaterial notions. For many, today's naturalism looks a lot like new-age mysticism, pantheism or Buddhism.
Posted by: SteveK | May 31, 2010 at 10:08 AM
SteveK,
For many, today's naturalism looks a lot like new-age mysticism, pantheism or Buddhism.
I don't know who you have in mind, but my impression is that most naturalists would say that they simple endorse one of the following (none of which entails mysticism, pantheism, or Buddhism of any sort):
(a) Only those entities required by our best physics exist (so, on this view, numbers exist)
(b) There are no causally efficacious non-physical things.
(c) The entire mental world depends for its existence on the physical world.
Each of these characterizations is compatible with Platonism about abstract objects, and none of these characterizations entails anything of the sort you suggested.
Posted by: Malebranche | May 31, 2010 at 01:05 PM
Malebranche,
I think you have woven the argument too tightly around the empiricism. First, our rational minds perceive the reality of numbers. Second, we use numbers in physics and elsewhere to help us understand reality.
Desire (or will) isn't causally efficacious? What reasons do you have for thinking this is true?
I have no reason to think this is true at all. I do have reasons to think the opposite is true.
Logic is part of the mental world. We perceive it to be immutable, and dependent on nothing (no thing).
I see no reason to think that logic can fail to exist or can be altered as a result of the physical world being altered.
Posted by: SteveK | May 31, 2010 at 01:48 PM
SteveK,
I have a couple of clarifying points.
First, an entirely adequate definition of naturalism defines it as the view that the entire mental world ultimately depends for its existence on the physical world. This is plainly inconsistent with theism, since according to theism the entire physical world ultimately depends for its existence on God, a mental substance.
Second, naturalism as defined in no way obviously entails that the laws of logic depend for their existence on physical things. Some naturalists (perhaps the early Russell) believe that abstract objects, such as numbers, universals, propositions, etc., are neither mental things nor physical things, but constitute a third kind of entity. The naturalist might maintain that there are at least three distinct kinds of entities: (i) physical things, (ii) mental things, (iii) and Platonic abstracta. They might even think that though it is contingent that physical and mental things exist, Platonic abstracta exist necessarily. I see no incompatibility between this view and naturalism as defined above. You assume (very controversially) that everything that exists is either physical or mental. That, however, is rejected by many philosophers, since Platonic abstracta are thought of by many to be a distinct kind of thing entirely.
Third, I don’t need to be a naturalist of any sort to make these points. I am not a naturalist. I think it is necessarily false. Nevertheless, I am still able to comment on entailment relations between naturalism and other propositions (such as ‘pantheism is true’ or whatever).
Fourth, since naturalism as defined does not entail that there are no numbers, it is no good to object to naturalism (as J.P. Moreland tries to do) by citing the existence of numbers.
Finally, you ask if desire (which I understand to be a mental state) is causally efficacious. I don’t know. But I can tell you what a naturalist could say. Some naturalists might say that mental states are identical with physical states, and physical states are causally efficacious. So, they would say, “Yes, desires are causally efficacious, but that’s only because they are physical.” Epiphenomenalists, on the other hand, will grant that desires are non-physical, but they simply deny that they are causally efficacious. Only physical states are causally efficacious. I gather that you disagree with these folks. I probably do too. But disagreement is easy. Refutation is what is so incredibly difficult.
Posted by: Malebranche | May 31, 2010 at 02:35 PM
Malebranche,
I would agree. It's described as a "bottom up" worldview. The problem with the Platonic abstracta of naturalism is that they require grounding. For example, a naturalistic "ought" requires grounding in a transcendent, necessary and immutable source. That makes either the Platonic abstracta, the mental, the physical or some unknown to be the grounding source = the rock bottom of the "bottom up" worldview.
However, nothing in a naturalistic worldview is transcendent, necessary or immutable because nature has not given us any reason to think that it has any such qualities. It's a mere logical possibility built upon nothing more. In other words, pure speculation without reasons for advancing the speculation.
Posted by: SteveK | May 31, 2010 at 03:41 PM
So, while naturalism may be true there are no reasons available that argue for it being true.
Posted by: SteveK | May 31, 2010 at 03:56 PM
?!
No need to argue for 'it being true.' We know the natural world exists. The question is whether anything exists outside it and the burden is on the one who says something does.
RONH
Posted by: RonH | May 31, 2010 at 08:07 PM
@RonH
I disagree, slightly. I think anyone who presents a perspective has a burden. These perspectives could be for the existence of something, for the non-existence of something, for our ability to know about the existence of something beyond, for the meaningfulness of talking about that beyond, and so on. I think merely pinning the burden upon the one who claims something exists beyond is too simplistic.
If we're, in the general sense, going to have a discussion, then all involved parties must be prepared to present and support their perspectives.
Posted by: MrSprinkleFingers | June 01, 2010 at 04:21 AM
Malebranche, I'm going to change the argument you presented above a little bit in order to make it easier for me to make my point. If I make a false move, I trust you to point it out.
For starters, I am going to treat Leibniz's Law
as a rule of inference rather than a premise in the argumentYour claim seems to be that an argument like the one below is a simple intensional fallacy:
(1) I can doubt the existence of any physical thing any time I consider it.
(2) I cannot doubt the existence of my self any time I consider it.
(3) Therefore, I am not identical with any physical being (by 1, 2 and Leibniz's Law).
The problem is that properties based on mental attitudes, like believing that P is true or doubting that P is true or loving X, usually do not obey Leibniz's Law.
You present another argument to exemplify this point:
(a) Lois Lane loves Superman.
(b) Lois Lane does not love Clark Kent.
(c) Therefore, Superman is not identical with Clark Kent (by a, b and Leibniz's Law).
This argument is manifestly invalid. The fact that it has true premises and a false conclusion is a dead giveaway of its invalidity. The underlying reason for its invalidity is that the 'property' of being-loved-by-Lois is not a real property subject to Leibniz's Law.
But there is an important difference between the terms involved in 1-3 and the terms involved in a-c. There are modal elements in the predicate terms that may well render them subject to Leibniz's law.
Adapting the Lois/Superman/Clark argument to make it better match 1-3, it would look more like this:
(A) Lois Lane can refrain from loving Clark Kent at any time she looks at him.
(B) Lois Lane cannot refrain from loving Superman at any time she looks at him.
(C) Therefore, Superman is not identical with Clark Kent (by A, B and Leibniz's Law).
This argument is unsound of course, but that is both A and B, turn out to be false. Lois does love Superman, but not in the way that A and B describe.
But argument A-C is not obviously invalid in the way that a-c is. Look at it this way. Suppose that Lois really did find that she couldn't fail to love Superman every time she looked at him. Doesn't that imply some interesting connection between those two individuals or, at least, between Lois and Superman's type of being? The mere sight of him (or a being of his type) is followed by irresistible love. Wouldn't that connection give her the power to identify Clark Kent as Superman, or at least as the Superman kind of being, because she would find herself compelled to love him whenever she looked at him? It looks to me like it would (finally, a super-power for Lois!)
Neither is argument 1-3 obviously invalid.
Posted by: WisdomLover | June 01, 2010 at 07:57 AM
Hi MrSprinkleFingers,
Thanks for your comment. I don't see where we disagree.
Here's a perspective:
Koukl concludes he exists because he's thinking; he couldn't be thinking if he didn't exist. Fine.
Then, he says he believes he 'also' has a physical body. But, he says, since his senses can deceive him he could be mistaken about this.
STOP!
Why does he need this also?
All he has concluded from his thinking is that he exists. He hasn't established an immaterial component to his existance. He concluded his existance without using his senses but that doesn't mean he has an immaterial component that would require the 'also' when he refers to his physical component.
The means by which he established his existence - I think therefore I am - does not imply this existence has an immaterial component. It works just as well for a purely material existence. The possibility that his senses could deceive him into believing he had a material existence doesn't change one iota.
So his argument fails. It all comes to a head around 4:25.
There. I gave a 'perspective': that Koukl's case for an immaterial mind fails. So it's my burden to say why and I did so. I think that satisfies my burden in that regard.
It should go without saying that my refuting Koukl's particular argument is not the same as my claiming there is no immaterial mind.
It might be that I believe there is no immaterial mind. But I didn't assert it so I'm not obligated to defend it. All I'm obligated to defend is my rejection of his particular argument.
It might be that I have no supernatural beliefs. Am I therefore obligated to defend the statement: the natural world is all there is?
Where do you disagree (slightly)?
RonH
Posted by: RonH | June 01, 2010 at 07:58 AM
"Try to imagine Descartes doing his thing without importing assumptions from his life in the world. Imagine Descartes is a brain in a vat without sensations or memories of the outside world. Where is he even going to get the idea of an immaterial self if you don't preload him with it?"
Since Descartes did, essentially, assume just what you've supposed is a knock-out punch. The case you ask us to imagine is not difficult at all.
Descartes claims to be unable to doubt in his own existence even if God is evil and bending all His power on deceiving Descartes (which is a far more troublesome assumption that your brain in the vat). Descartes does not have this inability when it comes to the physical world. That's why he thinks that mind and matter are distinct.
Posted by: WisdomLover | June 01, 2010 at 08:26 AM
Yes, but I think we are all missing one key point that Greg is making in his video. The point is that we have to have the ability to reason and think logically before we can observe and talk about the natural world around us. On that point, strict forms of naturalism fail because the claims are self defeating.
Posted by: John Hellstedt | June 01, 2010 at 09:28 AM
WL,
As far as I know, Descartes assumed that if he detected a thinker then the thinker had to be him.
Kierkegaard called Descartes out on this but I got it a long time ago from my friend Al who seemed to have got it on his own but for all I know now got it from Kierkegaard.
I assume Descartes imported this assumption from his life in the world. Maybe I'm wrong there but I can't think where else he might have gotten it.
I doubt that Descartes made his best efforts on this - he had certain conclusions he wanted to get to and wouldn't want to shut the project down at the outset.
Here are the exact same mistakes repeated by Koukl.
1) I think, therefore I am doesn't distinguish between a material I and a non-material I. It is entirely agnostic on the subject.
2) We certainly have sensory evidence for the material body. Sweeping this evidence off the table is the worst thing you can do with it. To claim you can go farther is to invent evidence contrary to what you have. If you do sweep the sensory evidence for the material body off the table then all you have is the I think, therefore I am which is still agnostic on the material/immaterial question.
I have the feeling I've encountered a named fallacy that covers this.
RonH
Posted by: RonH | June 01, 2010 at 09:40 AM
I think RonH is right in that the cogito ergo sum does not, in and of itself, prove immateriality.
Koukl did not present it as such a proof. He presented it as the proof of actual knowledge and of proof of non-sensory knowledge (the primary (only?) way of knowing the material world).
He then presumes the immateriality of the self.
But this presumption he can also demonstrate to be true, although he has not presented the argument here, in this argument for knowledge.
Posted by: Daron | June 01, 2010 at 10:51 AM
RonH,
There are reasons, currently under debate, for thinking something like that does exist. I've given one reason, but there are more. Of course, nothing has been proven in the scientific sense, and likely won't ever, but the burden is no longer exclusively on our shoulders. If you disagree with the reason(s) presented, it it your burden to give a reason-based rejoinder that goes beyond speculation or mere logical possibility.
Previously I said:
What reasons do you have for thinking nature has "informed us" that it has these qualities such that logic can be considered necessary and immutable?
Posted by: SteveK | June 01, 2010 at 10:56 AM
Daron,
Koukl says "I can be more confident of my knowledge about something that is supranatural than something that is in the natural world" at 4:32.
That statement is based on the congnito ergo sum and it seems to be a conclusion: we can know immaterial things.
RonH
Posted by: RonH | June 01, 2010 at 11:48 AM
SteveK,
We seem to be changing the subject. Hm.. I should really be asking Why? But OK.
What's logic do?
Logic models some basic aspects of how things are or can be.
Or maybe:
Logic models some basic aspects of how things seem to be or seem to be able to be.
Or is logic something else?
Maybe you would say it IS the things I say it only models?
RonH
Posted by: RonH | June 01, 2010 at 11:56 AM
"Descartes assumed that if he detected a thinker then the thinker had to be him."
This critique is a joke. I say this with some trepidation because it does actually appear to be Kierkegaard's and I hate to say such things about the arguments of geniuses (which Kierkegaard certainly was).
Let's spell it out further. The claim is that Descartes is involved in this argument:
1) "x" thinks
2) I am that "x"
Therefore:
3) I think
Therefore:
4) I am
Descartes is wrong, according to this critique, because premise 2 begs the question.
Here is the problem:
Descartes' argument is this:1') I think.
Therefore:
2') I am.
Notice that the move from line 1' to line 2' in the actual Cartesian argument is exactly the same as the move from line 3 to line 4 in the critique's reconstruction.
What that means is that critique grants that the Cogito argument is logically valid. What is at issue is whether Descartes' Premise "I think" is true and knowable.
The critique of Descartes assumes that Descartes believes that he thinks because he first believes that something thinks and then assumes (without justification presumably) that he is that thing.
Anyone who reads Descartes for more than five minutes without simply trying to dismiss him will realize that this is not the way he argued. His point was that any effort to deny the premise was self-defeating. And just a few minutes reflection on that will show that he was absolutely right about that.
Let's try to deny Descartes' premise:
Effort 1:
I hereby boldly deny that I think!
Oh...wait. I had to be bold. I had to understand a claim. I had to assert that claim is false. But every one of those actions is a type of thinking on my part.
Effort 2:
I deny that I think.
No...I still had to think to do that.
Effort 3:
I doubt that I think?
Nope...sorry, my doubts are among my thoughts.
So Descartes' reasons for believing that He thinks have nothing to do with some prior observation of thought that he makes coupled with the identification of himself with the thinker. They have everything to do with the self-defeating character of making the claim that one is not thinking.
Posted by: WisdomLover | June 01, 2010 at 12:42 PM
BTW, Descartes may well be committed to this argument (and the argument is sound in any case:
1) I think
Therefore:
2) I exist
Therefore:
3) There exists at least one thing that thinks.
That is, Descartes' cogito proves the existence of the mental.
So the issue has never been whether matter-independent mental substances exist. As if matter were somehow a given and we have to decide whether there's something else and whether mind is that something else.
What's a given is mind. The issue is whether any mind independent material substances exist.
I've certainly never seen a good or challenging argument to suggest that they do. (Descartes own efforts on this front fall short).
Posted by: WisdomLover | June 01, 2010 at 12:58 PM
WL,
Why can Descartes excuse himself from asking Is the thinker me? by simply saying That's not the way I argue?
Why does argument fail to establish the existence of matter? Do you doubt matter exists? If not, why mention this failure of argument?
RonH
Posted by: RonH | June 01, 2010 at 03:00 PM
WisdomLover,
I don’t think the modal points do much work to help the argument.
To illustrate, suppose that God made some rational creature and equipped the creature with cognitive faculties such that the creature could not doubt that water exists but could doubt that H2O exists. Call the creature Aqua. We now may develop the following argument:
(P1): Water has the property being such that its existence cannot be doubted by Aqua.
(P2): H2O lacks the property being such that its existence cannot be doubted by Aqua.
(P3) If a and b do not share exactly the same properties, then a is not identical with b.
(C4) Therefore, water is not identical with H2O.
This argument is bad and seems to be a parity of the Cartesian argument rehearsed by Koukl.
Posted by: Malebranche | June 01, 2010 at 03:03 PM
"Why can Descartes excuse himself from asking Is the thinker me? by simply saying That's not the way I argue?"
For the same reason that any arguer can excuse themselves of defending an argument that they do not advance...they do not advance it.
Descartes has different reasons for thinking that his first premise is true than those presupposed by the critique's reconstruction. He is under no obligation to defend his first premise as the critique proposes.
All parties agree that his argument is valid. So that, as they say, is that.
"Why does argument fail to establish the existence of matter? Do you doubt matter exists? If not, why mention this failure of argument?"
What no argument I've seen has been able to establish is the existence of mind-independent matter. Indeed, I haven't seen an argument to show that the idea of mind-independent matter has any coherent content. So I have serious reservations about whether the stuff is even possible, let alone actual.
But I'll grant you all the mind-dependent matter you like.
Posted by: WisdomLover | June 01, 2010 at 03:33 PM
Malebranche-
The inability in question is not a simple limitation in cognitive faculties. In the argument for the distinction between mind and matter, the inability in question is a logical inability. Every effort to doubt my own existence provides, as its logical consequence, proof of my existence. This is not the case with every effort to doubt the existence of, for example, my brain.
This wrinkle is not something that I think can be easily captured in the Lois and Clark or the Aqua examples. For the sake of argument, I'm willing to grant that Lois and Clark, even my version, is more like the Aqua case than it is like mind and matter case and may be problematic in the same way.
(I should note that I do not think that water is identical to H20...H20 is a useful predictive model for water. But it is no more water than a Newtonian description of a wheel is a wheel...so I'm not sure that Aqua is a cogent counterexample.)
Posted by: WisdomLover | June 01, 2010 at 03:54 PM
WL,
I see your point better now and apologize for making you repeat it.
However, I still think Descartes has some more duties. There have to be experiences carried into the exercise in order for him to answer himself: What do you mean by I? What to you mean by think?, and finally, ala Bill Clinton What do you mean by am? It takes a lot to answer these questions. Descartes needs to have definitions of I, think, and be at hand but he is also supposed to be in a state of radical doubt.
I just realized something else. You say Descartes is justified I think. cannot be denied. I have just received an mass email from Koukl that says:
What did Descartes do about the option of withholding judgement for lack of information?
RonH
Posted by: RonH | June 01, 2010 at 04:40 PM
Hi RonH
Something in that statement is based upon the cogito, but it is not the immateriality.
I was going to say that the cogito does not demonstrate immateriality, and that probably Decartes knew it (since he wasn't arguing that) and probably Koukl knows it as well (but as you will see, as I continued to type I rethought that conclusion).
What is concluded from the argument is that something can be known (Descartes), and
there are ways to know that are not derived via the senses (ie, the way material things are perceived) (Koukl). He gives the next example when he says how we know that the laws of logic are known.
Koukl himself refers to another method of acquiring knowledge about the self, and that is the sensory perception of the physicality of the self. But the senses can be fooled (in the extreme this lead to the skeptical position against which Descartes was arguing), so we have no confidence that the physical aspect of the self exists. Yet we do know and have perfect confidence that the self exists. So it may or may not be physical, but we have no confidence in the argument for its physicality, or materiality.
On the other hand, upon further reflection, it actually does give more confidence in the supranatural than in the "natural" as we know there is a self but do not know that it is extended in space. Therefore we can doubt that it is extended in space. Therefore it might not be. But it is not the case that it might not exist. So the skeptic, he who doubts the conclusions of the senses, in fact, must (almost) admit it is immaterial - because we know it exists and don't know the physical does.
With no confidence the physical exists but absolute confidence I exist, I am left, even without the further arguments for the immateriality of the self, confident that I have an immaterial aspect. And that I know it.
Posted by: Daron | June 01, 2010 at 09:46 PM
Ron-
Descartes does, of course, have meanings in mind (pardon the pun) for all the terms you mention. And I imagine they're the standard ones. But even though he's in a state of radical doubt, he still finds that it is self-defeating to doubt "I think" and "I exist", however laden with prior experience and theory the terms involved might be.
What Descartes is moving toward is the idea that there are some things that we can be certain of, in spite of the evil genius, at least so long as we attend to them, and without the need of argument. He allows that we may have used all sorts of arguments and experiences in the past to get us the point that we are now able to see, without reference to argument or experience, that we are unable to doubt them. "I think" and "I exist" are two examples of such things, but so is "7+5=12". It's worth noting that Descartes never says "I think; therefore, I am" in the Meditations (the cogito argument comes from the earlier Discourse on Method). By the time we get to the Meditations, Descartes has realized that the key insight is that he could not deny "I think" to be true, even under radical doubt.
On your second point about withholding judgement, Descartes also had a lot to say. He argued that all the sin and error that humans are responsible for comes from the fact that they do not withhold judgement when they lack adequate reason. Obviously, he must have believed that "I think" was one of the things he had adequate reason for. What is his reason? Simply the fact that any effort to deny, or even to withhold judgement on the claim proves that the claim is true. Withholding ones's judgement is, after all, also a case of thinking.
Now, clearly there is also the possibility of simply not making or withholding a judgement about the "I think". I do this all the time, for example, when I am sleeping or watching television. I am neither making nor withholding judgment about the "I think". When I am watching television, you might be able to argue that I am not thinking at all ;-) But Descartes' point was only to apply to the case where I am actually attending to the proposition "I think". So, though my mind might have winked out of existence during reruns of "Walker, Texas Ranger", whenever I snap out of it and attend to the proposition "I think", I find that the only thing I can coherently do is to affirm it.
Posted by: WisdomLover | June 02, 2010 at 03:12 AM
WisdomLover,
You note that the following is true:
Cogito, Ergo Sum: Necessarily, if I am doubting my existence, then I exist.
You go on to note that the following is false:
Cogito, Ergo Corpus: Necessarily, if I am doubting the existence of my body, then my body exists.
But what I am failing to see is how the truth of Cogito Ergo Sum and the falsity of Cogito Ergo Corpus shows that the mind is not physical. The predicate being such that, necessarily, I cannot doubt its existence seems to be no more genuine a property than the property being loved by Lois.
Anyway, I’m not seeing the argument. Perhaps you could outline it clearly.
Posted by: Malebranche | June 02, 2010 at 06:36 AM
Daron,
Our senses give us a very high degree of confidence that we exist and, specifically, that we have a physical side.
There is no corresponding thing that gives us a corresponding confidence specific to an immaterial side.
Parsimony suggests we doubt an immaterial side.
RonH
Posted by: RonH | June 02, 2010 at 10:06 AM
"Our senses give us a very high degree of confidence that we exist and, specifically, that we have a physical side."
How so? Our senses provide us with mental images. This is evidence that we have a mental side. I'm not seeing any evidence at all for matter (mind independent matter mind you).
Posted by: WisdomLover | June 02, 2010 at 10:14 AM
What he said.
Posted by: Daron | June 02, 2010 at 11:03 AM
Specifically, my senses give me confidence that I exist because there must be an I that is doing the sensing.
Because I am trapped in the sensing agent I don't have a high confidence that the senses are sensing a material external world .... unless I believe in God, of course.
Posted by: Daron | June 02, 2010 at 11:06 AM
Malebranche-
I guess the point is that the cogito proves that thinking things exist. So there is something mental in the world.
What I don't know is whether there is anything physical in the world. Or whether the idea of the physical is even coherent.
I also, for example, don't know whether there is anything schmysical in the world. With that said, suppose that I have no proof that minds (which I know to exist) are not also schmysical. Am I somehow obligated to show that minds are not schmysical?
Posted by: WisdomLover | June 02, 2010 at 11:12 AM
RonH,
As WL has already pointed out, everything we know about reality comes to us in the form of mental perceptions. You can doubt the extra-mental world, but you cannot doubt the mental world. The moment you doubt it, you confirm it.
You can dream up scenarios where all of your mental perceptions are wrong (brain-in-vat), however that means your perception of the extra-mental world is also wrong.
Posted by: SteveK | June 02, 2010 at 01:05 PM
WisdomLover,
I guess the point is that the cogito proves that thinking things exist. So there is something mental in the world.
It is important to see that these remarks constitute no reason whatsoever to think there are non-physical entities. At best all we can get from these remarks is the following argument:
(1) If I am thinking, then something that thinks exists.
(2) I am thinking.
(3) Therefore, something that thinks exists.
Notice that I asked you to argue for the truth of the proposition Some non-physical entity exists. Notice furthermore that there is a massive gulf between Something that thinks exists and Some non-physical entity exists. To bridge the gulf you need the following principle:
Mentalism Principle: if something that thinks exists, then some non-physical entity exists.
But now the question becomes, “Why accept the Mentalism Principle?” Without independent support for the Mentalism Principle, you have given no reason to believe that Some non-physical entity exists. Why think that no purely physical object can think? That cannot just be asserted against those who don’t believe it. It must be argued for. So what true premises do you have that validly deliver the Mentalism Principle?
Posted by: Malebranche | June 02, 2010 at 03:24 PM
If by "physical" you mean "mind-independent material substance" then the presence of something mental implies the presence of something non-physical.
But the cogito proves the existence of something mental.
Posted by: WisdomLover | June 02, 2010 at 04:00 PM
Malebranche,
If you are confident that "something that thinks, exists" and you are confident that this knowledge didn't come to you via the 5 senses (which is true), then what are the other options available for you to become aware of its presence? I don't know of any.
Posted by: SteveK | June 02, 2010 at 04:07 PM
"(a) Only those entities required by our best physics exist (so, on this view, numbers exist)
(b) There are no causally efficacious non-physical things.
(c) The entire mental world depends for its existence on the physical world."
(a) and (b) entail (c). There's nothing physical in that relationship. It may be that the mental world depends on the physical world, but the existence of logical relationships means that it is not the case that there are no causally-efficacious non-physical things. (Triple negatives scare me, by the way).
Here's another example. Suppose I choose not to kill my neighbor because I become convinced that it is wrong to kill the innocent because human beings have intrinsic dignity. Several things are going on here. First, the basis for my new moral outlook has no physical referent, intrinsic dignity. Second, my mental change, from potential killer to repentant sinner, is the consequence of my accepting a new belief. Here, the entire cognitive act--the reading, the understanding, the reflecting, the agency, and the believing--and the belief on which this act focused are causally efficacious in changing my character (or putting me on the path to true virtue).
Sure, one can physical components in this narrative. But it is clear that my change in belief and disposition is not the proper subject of physics.
Posted by: Francis Beckwith | June 02, 2010 at 09:00 PM
Francis,
the existence of logical relationships means that it is not the case that there are no causally-efficacious non-physical things.
I see no reason to believe this and good reason to think otherwise. Entailment, after all, is not a causal relationship. All men being mortal and Socrates being a man does not cause Socrates to be mortal. That is just a confusion. I agree with you that if entailment were causal, it would be a good candidate for a non-physical entity with causal power. But the entailment relation is plainly not causal.
Posted by: Malebranche | June 03, 2010 at 11:22 AM
Malebranche,
Entailment is causally-efficacious according to the nature of reason. It is a mental "ought". Entailment is a characteristic of reason such that without it, reason would not be reason and would fail to exist.
For those that say it, it makes no sense to say that mental states are identical to brain states because reason and entailment would be a physical thing. What physical thing could could have the quality of "oughtness"? None.
Posted by: SteveK | June 03, 2010 at 12:39 PM
Descart spent too much effort.
All he needed to say was that to deny my existence is to affirm it.
Posted by: Damian | June 03, 2010 at 02:28 PM
@RonH,
If you agree claims about there existing nothing outside of the natural world must also carry a burden, then we agree. I simply don't think the original statement clearly communicate the idea, and seem to provide a lop-sided perspective.
Posted by: MrSprinkleFingers | June 04, 2010 at 06:12 AM
Malebranche-
It's curious that you are emphasizing the claim that there are no causally efficacious non-physical things. As I'm sure you know, the real Nicolas Malebranche put forward a doctrine called occasionalism. Occasionalism held that there are no causally efficacious things, period. Except for God...who is non-physical.
While I don't buy into Malebranche's occasionalism I do think it has this to recommend it: it is virtually impossible to see how there could be any causal interaction between matter-independent mental substances and mind-independent material substances.
(Of course, I tend to deny that there are any mind-independent material substances...so that's my explanation of the impossibility)
Posted by: WisdomLover | June 05, 2010 at 05:26 AM
WisdomLover,
You're right. Malebranche defended the claim that x has causal power only if x is identical with God. Pretty interesting, in my opinion.
As far as historical figures go, however, I think that neither Descartes, Malebranche, or Spinoza held a candle to Leibniz, who argued persuasively that Something is a substance only if it has genuine irreducible causal power (which, by the way, is the reason why, strictly speaking, there are no chairs, computers, books, or artifacts of any kind). Given the truth of that conditional, it would follow from occasionalism that there is exactly one substance, which just is the pernicious doctrine of Spinozism. And that, as a matter of fact, is exactly what Leibniz thought of occasionalism (that occasionalism is simply Spinozism in sheep's clothing).
But Leibniz too was an idealist, so, strictly speaking, he also thought that only non-physical immaterial substances have causal power. With Leibniz, Malebranche, and Descartes, I agree naturalism is false,since there are non-physical causally efficacious substances.
Posted by: Malebranche | June 05, 2010 at 07:40 AM