October 26, 1992
1. Explain clearly and in your own words what error Plato’s first and fifth argument have in common. Do not just label the mistake, but explain why it is a mistake.
Plato’s first and fifth argument for the immortality of the soul both make the same basic mistake. The mistake is not an obvious one but once it is seen it is impossible to ignore. Both arguments are founded on the premises that being alive is the opposite of being dead, and to exist is the opposite of to not exist. Both premises are apparently correct but upon close inspection the second is seen to be a fallacy. Plato, or anyone else for that matter, cannot treat existence as an opposite of inexistence. Existence is not an opposable property. It is not a property at all. Even if existence could be treated as a property, which it patently cannot, inexistence can never even be thought of as being a property. To say something, like the soul, has the property of inexistence (or does not have the property of inexistence) is to presuppose that it exists, for it could not allow the property of inexistence, or any other property, without in fact existing.
Existence is not an attainable property, as Plato asserts, but a state. It is in fact a state without which no properties are attainable. Furthermore the state of inexistence is the state that with which no properties are attainable. To say something does not exist is to say that it must exist in order to be able to not exist, which is ridiculous. It is this paradox which ruins both the first and the fifth arguments for the immortality of the soul. Because Plato is presupposing the soul’s existence, he is not truly giving us an argument for its existence, but merely the proof that “if” it did exist it couldn’t not exist. This “if,” along with treating existence and inexistence as properties, are the reasons Plato’s arguments are not acceptable.
2. Explain why Socrates says that philosophers practice dying and death; in what respect does this show that Socrates’s conception of the soul differs from Descartes’s?
Towards the beginning of Plato’s Phaedo, Socrates makes the statement, “that the one aim of those who practise philosophy in the proper manner is to practise for dying and death.” Although this may appear to be a rather flippant comment to assuage the worries of Simmias and Cebes, I think it illustrates an important contrast between the conceptions of the soul entertained by Socrates and by Descartes.
Socrates and Descartes both believe that the only way to assuredly achieve truth is through the soul (“mind” to Descartes). This is because the body is easily deceived because of the fallibility of the senses. What we might clearly and distinctly perceive with the senses, like color or size or taste, are biased by the body’s interpretation of the stimuli. For example: one man’s chocolate is another man’s asparagus. Both Descartes and Socrates believe that the man who can discover truth is he who, in Socrates’ words:
approaches the subject with thought alone, without associating any sight with the thought, or dragging in any sense perception with his reasoning, but who, using pure thought alone, tries to track down each reality pure and by itself, freeing himself as far as possible from eyes and ears, and in a word, from the whole body, because the body confuses the soul and does not allow it to acquire truth and wisdom whenever it is associated with it.
Descartes says essentially the same thing in the First Meditation with:
Whatever I have up till now accepted as most true I have acquired either from the senses or through the senses. But from time to time I have found that the senses deceive, and it is prudent never to trust completely those who have deceived us even once.
The difference between their philosophies is that Descartes believes it is possible to dispel all previously held beliefs and clear from the mind all the influence of the body. In this way it is possible to examine life and the universe and discover truth and therefore view the world in an honest light in order to lead a better life. Descartes thought achieving truth and perfect knowledge was an attainable goal.
Socrates thought true philosophers believe, “as long as we have a body and our soul is fused with such an evil we shall never adequately attain what we desire, which we affirm to be the truth.” Furthermore he stated that, ” everywhere in our investigations the body is present and makes for confusion and fear, so that it prevents us from seeing the truth.”
Socrates reasoned that, “if we are ever to have pure knowledge, we must escape from the body and observe matters in themselves with the soul by itself.” The only way the soul can be separated from the body, said Socrates, is through death. So although both Socrates and Descartes believed pure knowledge is attainable, Socrates claimed that it wasn’t so until after death. Socrates maintained that there is no reason for the true philosopher to be afraid of death because only after death can a philosopher’s goals be achieved. Descartes’s view is that pure knowledge is the armor which the soul can use to bravely face death. The difference between their beliefs is whether the soul can achieve pure knowledge before death.
3. Explain Descartes’s dream argument as presented in the lecture and explain why one might think that the argument cannot establish its conclusion if Descartes relies on facts about actual dream experiences to support the premises of the argument.
Descartes begins his Meditations with his dream argument. In his attempt to clarify when he can be sure of anything, Descartes explains that his senses are not reliable sources of information because they are often incorrect. Since his senses are easily misled, he looks to his thoughts as possible reliable sources. These too he discovers can sometimes deceive. This is the point at which Descartes proposes his dream argument.
Since he sometimes has dreams in which he is apparently awake, how can he ever know if he is really awake or merely dreaming that he is really awake? He extrapolates this into the doubt that he can ever be sure of anything because there is no way to prove he is not dreaming, since dreaming experiences are sometimes indistinguishable from waking experiences, and dream experiences are seldom reliable. This argument, like so many others we have studied, places the philosopher in such an extreme state of doubting that he cannot be sure of anything without relying on God to save him. Descartes’s deus ex machina is that a good and benevolent God would never allow us to be so deceived and so we need not doubt everything. But then should we not ask how we know that God is not merely a dream? Descartes answers this question with his typical circular logic, relying on what he is trying to prove to prove what he is trying to prove.
I believe that one might find that the argument cannot establish its conclusion if Descartes relies on facts about actual dream experiences to support the premises for two reasons. First, since dream experiences are sometimes so identical to waking experiences as to be indistinguishable, how can Descartes then go on to rely on facts about “actual” dream experiences? It would seem to me that he has no criteria for defining what an “actual” dream experience is. How can Descartes claim to rely on facts about “actual” dream experiences when, by his own admission, he might really be relying on facts about “actual” waking experiences? I don’t think he can. Second, since Descartes firmly believes that dream experiences are not a reliable means of arriving at true belief, how can dream experiences support facts about themselves? By Descartes own explanations of their nature, they cannot.
Descartes’s first premise in the dream argument, “I do not know that [I am awake] if I merely dream that [I am awake],” and second premise in support of it, “Dreaming is not a reliable means of arriving at true belief,” are self-refuting. We know that a true conclusion cannot be drawn from false premises. Therefore if we admit that Descartes first premise, by its own explanation, is self-refuting, then we must also admit that the conclusion to Descartes’s dream argument is false.
4. Briefly explain the Cartesian Circle.
Once Descartes places himself in a state of extreme doubt, he explains that his only method of being sure of anything is to clearly and distinctly perceive it. He goes on to explain that he cannot clearly and distinctly perceive anything until he can prove the existence of God. So Descartes, regarding only what he clearly and distinctly perceives as true, proves, he believes, the existence of God. Armed with the knowledge of the existence of God, Descartes begins his task of finding out about what he can now clearly and distinctly perceive.
Descartes has used something X (clear and distinct perception) he says he cannot have in order to prove the existence of something Y (God), which is what he needs in order to prove he has something X. How can he purport to achieve X if he must use X as a means of achieving X? He cannot. This chain of events is described as the Cartesian Circle.
5. Why does human error present a problem for Descartes and how does he solve that problem in the Fourth Meditation?
Human error presents a problem for Descartes in the Fourth Meditation because in order to hold firm his previous deductions he must also conclude that he is incapable of ever going wrong.
… I know by experience that there is in me a faculty of judgment which, like everything else which is in me, I certainly received from God. And since God does not wish to deceive me, he surely did not give me the kind of faculty which would ever enable me to go wrong while using it correctly.
Descartes solves this problem by explaining how human error is possible without it being the fault of God. His explanation is similar to the one Douglas Adams uses to prove that the population of the universe is zero.
It is known that there are an infinite number of worlds, simply because there is an infinite amount of space for them to be in. However, not every one of them is inhabited. Therefore, there must be a finite number of inhabited worlds. Any finite number divided by infinity is as near to nothing as makes no odds, so the average population of all the planets in the universe can be said to be zero. From this it follows that the population of the whole universe is also zero.
Adams, Douglas. The Restaurant at the End of the Universe, Pocket Books, NY,NY.1980
Descartes’s argument is that our will, or our freedom of choice, is infinite while our knowledge is finite. “The scope of the will,” says Descartes, “is wider than that of the intellect; but instead of restricting it within the same limits, I extend its use to matters which I do not understand.” Therefore, he reasons, it is easy to make mistakes since we can choose anything but we can only be correct about a certain number of choices.
6. Explain Descartes’s conception of the relation between the mind and the body.
Descartes’s conception of the relation between mind and body is difficult to explain. Descartes believes that, contrary to what we would assume, the mind is known with greater certainty than the body to exist. This is because, he explains, although a malicious demon could very probably cause us to falsely imagine owning hands and feet and bodies, he could not cause us to falsely imagine thinking if we do not in fact think. That would be tantamount to the statement: This sentence is false.
If the sentence is in fact false, as it asserts, then it is true. But if it is true then it is in fact false and therefore true. Descartes, or any mind, cannot be forced to “pretend” to think or “be fooled into thinking” it is thinking because either way it would be thinking. On the other hand there are no facts about “the body” which might not be falsehoods or imaginary. Since the mind absolutely and definitely exists, while the body may or not exist (we can never really know), the mind can be examined much more clearly and with much more certainty than the body.
I think that Descartes’ belief that the mind is not only known with greater certainty to exist than the body but is also capable of being better understood is one of the few beliefs in the Meditations with which I find I can agree.
7. Explain Descartes’s argument for the real distinction between the mind and the body.
Descartes’s argument for the real distinction between the mind and the body, “is that the mind and the body have essential properties that are contradictory,” (Ludwig, “Four or so arguments about the relation between mind and body”. 1992) and therefore the mind and body are necessarily non-identical. Descartes gives two structurally identical forms of this argument. The first utilizes the property of extension and the second that of divisibility, and both use Leibniz’s law.
Descartes states that extension and divisibility are necessary properties of a body. He also states that non-extension and indivisibility are necessary properties of a mind. Since Leibniz’s law tells us that two things are identical if and only if they share all their properties, and therefore are non-identical if they share opposite properties, mind is necessarily not identical to body.
8. What is Descartes’s response to the dream doubt in the Sixth Meditation?
In the Sixth Meditation Descartes returns to the dream doubt and comes up with a response to it. Knowing that the major difference between being asleep and being awake is that dreams are never linked by memory, which more often than not is correct memory, in the same way that waking experiences are is the tool Descartes uses to refute the dream doubt. Descartes proposes that if a person suddenly appeared seemingly from nowhere and then suddenly disappeared seemingly to nowhere, it would be reasonable to assume that this person was either a ghost or that he was part of a dream. This is because in waking experiences we (unless drugged) can remember a person’s origins and (immediate) destinations. It is much simpler to assume the latter explanation and we can therefore determine the different states when awake.
William Poundstone proposed this test, based on Descartes’s theory of the connectedness of waking memories:
Keep a book of limericks by your bed. Don’t read the book; just use it thus. Whenever you want to know if you are dreaming, go into your bedroom and open the book at random. Read a limerick, making sure it is one you have never read or heard before. Most likely you cannot compose a bona fide limerick on a moment’s notice. You can’t do it when awake, and certainly not when asleep either. Nonetheless, anyone can recognize a limerick when he sees it. It has a precise rhyme and metrical scheme, and it is funny (or more likely not funny, but in a certain way). If the limerick meets all these tests, it must be part of the external world and not a figment of your dreaming mind.
Poundstone, William, Labyrinths of Reason, Doubleday Press, NY, NY, 1988
Descartes’s response is basically that since it is not impossible to tell the difference between waking and dreaming experiences the dream doubt is no longer any real cause for skepticism about the external world.
9. Explain Berkeley’s strategy in responding to skepticism about the external world.
Berkeley’s strategy in responding to criticism about the external world is very different compared to the strategies employed by Socrates or Descartes. Rather than try to explain the external world or give definitions or explanations of what most think able to be known using common sense, Berkeley attacks skepticism itself.
The skeptical argument relies on two assumptions:
- The mind and the world are logically independent.
- The evidence we start out with (a priori knowledge) is only about the mind.
Berkeley does his level best to refute this argument rather than fall into its trap. Berkeley claims that all we think of as ordinary physical objects are merely collections of ideas. This claim dissolves the problems Descartes and Socrates raised about our knowledge of the external world by denying that there is a distinction between what is “real” and what is perceived. If, as Berkeley believes, there is no difference what is the “real” world and what we perceive as such then we cannot be skeptical about what we are perceiving. What would appear to be a monumental task Berkeley accomplishes by simply saying that there is no such thing as the “real” world and everything we assume to be a part of the “real” world is an idea. All we perceive, says Berkeley, are ideas. These ideas are the “real” world and all are within our minds.
Since, as Berkeley would have it, the mind and the world are not logically independent, we have nothing about which to be skeptical and therefore have no reason for skeptical arguments about the external world.
10. What was the criticism advanced against the argument from illusion in the lecture?
Berkeley’s argument from illusion won’t hold water. Or at least it won’t hold an oar in the water. The “oar in water” example is the one we used most often in class to refute Berkeley’s argument from illusion. When we see what we know to be a straight oar in water it appears to be bent. According to Berkeley what we perceive is a bent oar and therefore it really is a bent oar because all we immediately perceive are ideas. In actuality however, even though we “see” a bent oar, our previous knowledge of the effects of water and light on objects allows us, no, forces us to immediately perceive “a straight oar that appears bent.” This is contrary to what Berkeley believes is happening. Whether the oar is in actuality bent is not important because our minds automatically tell us what we are seeing is not “reality”. According to “reality” we know that the oar is straight regardless of our immediate perception of it.
11. Explain the criticism advanced against the argument from relativity given in the lecture.
The main mistake in Berkeley’s argument from relativity is that he ignores the well known fact that “everything is relative”. In his first premise to this argument Berkeley asserts that an object can’t have two contradictory properties. This is true; an object cannot be both hot and cold or big and small. In his fifth premise he states that , “For any quality we might seem to perceive in an external object, depending on our state, we may perceive a contradictory quality.” He then uses these two major premises to conclude that, “we never perceive any quality in external objects, but only ideas in our own minds.” The method given in class to contradict this argument uses this example:
Suppose we take a flea and a man both contemplating a chihuahua. The man thinks to himself: such a tiny animal. The flea thinks to itself: Lo, behemoth!
It would seem, at least to Berkeley, that the chihuahua has the contradictory properties of smallness (to the flea) and bigness (to the man). Upon closer inspection though we can realize that it is absurd to say that these qualities are actually inherent in the chihuahua but rather they are qualities assigned to the chihuahua by the flea and the man. As we said in class, if the man and the flea were able to communicate (!!) and agree upon a standard of measurement then the problem would be resolved. For example, rather than say that the chihuahua is big or small, if the man and flea both said, “This chihuahua is a little more than a foot and a half tall and a little less than a foot wide,” than Berkeley could no longer claim that the bigness or smallness was “in” the chihuahua. It is important, not just in the study of philosophy, to remember that all objective properties are relative and not immutable. If two different minds agree on a standard than Berkeley’s argument crumbles.
12. Explain at least one error in Berkeley’s argument to show that we cannot conceive of something existing unperceived.
Berkeley’s argument that we cannot conceive of something existing unperceived falls into a semantic trap, or what we have described as the result of his ‘poverty of vocabulary’ intruding upon his arguments. The problem is his confusion of the terms ‘imagine’ and ‘perceive’ (and probably ‘conceive’ also). Berkeley explains in his first premise to the argument, “Nothing can exist unperceived unless we can conceive of something existing unperceived.”
I think this is true, not exactly a revelation, but true nonetheless. His next premise asserts that, “To conceive of something is to imagine it.” This point, I think, is arguable, but we’ll assume it’s true for our purposes. His third premise says that, “To imagine something is to have it in the mind, i.e., to have a mental image of some sort in the mind.” This premise is true. Berkeley is not too far from ‘common sense’ up to this point in his argument. In the fourth premise though we see where Berkeley has made one of his semantic mistakes.
“To have a mental image in mind is to perceive it,” says Berkeley. What he is doing in this premise is confusing perception with conception. To have a mental image in the mind is not the same as to perceive what the image is. Barring any beliefs in The Force or ESP, it is generally accepted that something must exist in order to be perceived. If something does not exist (it is ludicrous to go even this far) it has no perceivable properties, as we have already determined. I think it is possible to conceive of something which does not exist. To conceive of something does not require that the something has any perceivable properties. Something which does not exist (just pretend, ok?) certainly does not have any perceivable properties and so it (!!) would be conceivable/imaginable. Berkeley’s fifth premise, “to conceive of something is to perceive it,” contains the same error.
13. Explain at least one objection to Berkeley’s claim that what we think of as ordinary physical objects, such as tables and chairs, are merely collections of ideas.
The easiest way to refute Berkeley’s claim that all that we think of as ordinary physical objects are merely collections of ideas is to attack his premise that whatever we are immediately aware of is what we perceive. This premise is part of the argument from the inseparability of sensations which is in turn a support for Berkeley’s argument for the claim that all we ever perceive are ideas. In the conclusion to this sub-argument Berkeley tells us that heat and pain are identical because we do not perceive from intense heat two distinct sensations, but merely one uniform sensation. He tells us that since both heat and pain are immediately perceived, they must be identical. One obvious error is that Berkeley is disregarding Leibniz’s law. Heat and pain may, in this instance, share the property (if it can be called such) of simultaneous occurrence. But they are not the same feeling. For example when one feels intense heat it is a one certain feeling, but when one feels pain, it is not necessarily the same feeling as is produced by intense heat. The pain of a skinned knee or a hangnail is definitely not the same pain as that of intense heat. Here is one of many possible examples of properties of heat and pain which are not identical. According to Leibniz’s law heat and pain can therefore not be identical either. This premise, which I think I have done a fair job of proving false, through its falsity refutes Berkeley’s main premise in support of his argument that all we ever perceive are ideas. Having done this it is now easy to see that the entire argument, for all intents and purposes, is false.