Reason as a Source for Knowledge Flashcards

Question

Criticism of the theory of tabula rasa (2): Do all complex ideas/concepts relate to impressions?

Answer 1

How is my concept of justice related to my sense impressions? How is my concept of freedom related to my sense impressions It seems very difficult to relate such complex concepts to patterns of sense experience. However - The empiricist may respond by saying that the fact that it is very difficult to explain these abstract concepts in terms of sense experiences is because the concepts themselves are vague. If we could pin them down so that they were more close to experience, we would have clearer concepts. But - an innatist can respond to the empiricists response by saying that different people may have different images/impressions of ideas like beauty and justice, but they all seem to share the same concept. This means that such ideas do not come from experience. They must be innate.

Answer 2

Relations concepts such as ‘being near’, ‘sameness’, ‘next to’, ‘on top of’ are very difficult for the theory of tabula rasa to account for. E.g. to say that the cat is on the mat, I need a concept of ‘on-ness’. And yet my sensation is only of the cat and the mat. ‘On-ness’ does not have a specific colour, sound or taste. Think of the concept of ‘sameness’. It has no particular colour, taste, smell and doesn’t seem to come through the senses.

Answer 3

Imagine a genuine tabula rasa, let’s say a statue that is given the ability to receive sense information, store it in its memory as ideas and combine the contents of this memory to create complex ideas. This is the idea developed by Condillac (1715-1780). He believed that such tabula rasa would eventually come to the level of understanding that we have. Many people say that Condillac’s statue would not be able to develop the level of understanding and knowledge that we have. They argue that the statue would receive a flow of uninterrupted sensations: noises, shapes, colours and tastes. But to even begin to form concepts, it would need to be able to recognise that two sensations are similar. It couldn’t do this without the concept of ‘sameness’ which would have to exists prior to experience. Without such interpretation, experience would be a ‘blooming, buzzing confusion’ (William James).

Answer 4

When a conclusion is proved to be true because it rationally follows from a series of premises which are themselves true.

Answer 5

Discovering truths about a claim by thinking about them

Answer 6

The method of intuition and deduction consists of two stages. 1. Rational intuition: we begin with an obviously true statement, i.e. one that we intuitively know is true, e.g. that 2 + 2 = 4. 2. Use the rational intuition as the starting point of a deductive argument. By constructing the deductive argument carefully and by using true premises, we establish a conclusion.

Answer 7

Analytic truth True in virtue of the meaning of the words E.g. “A bachelor is an unmarried man” or “triangles have three sides” To deny an analytic truth is to commit a logical contradiction: just try imagining a triangle with four sides Synthetic truth True in virtue of how the world is E.g. “Grass is green” or “water boils at 100°c” To deny a synthetic truth does not entail a logical contradiction: I can unproblematically (i.e. without contradicting myself) imagine a world in which the grass is pink.

Answer 8

An analytic a priori statement is one such as ‘all bachelors are unmarried’. It is true because of the meaning of the word ‘bachelor’ and this is known through the use of reason. An analytic a posteriori statement is impossible. It is impossible to establish an analytic truth through the use of experience. A synthetic a priori statement is one that tells us something about the way that the world is (it is synthetic), but is reached by a priori reasoning, i.e. reasoning that requires no experience. A synthetic a posteriori statement is one such as ‘the grass is green’.

Answer 9

Descartes, in meditations on first philosophy, subjects all of his beliefs to extreme doubt, leading to him imagining that the physical universe, including his body, could be illusory. He imagines that there could be an evil demon deceiving him into believing that everything he perceives is true, when it is, in fact, false. This extreme doubt is known as global scepticism: we cannot know anything for certain. All beliefs except one: He exists. If he doubts his own existence then he must be doubting, and if he I doubting he cannot be nothing. Although he cannot prove he has a body, he can prove he is a thing that doubts, he is a thinking thing: a mind. (the cogito) Descartes observes that this item of knowledge (that he exists) was a ‘clear and distinct idea’. Descartes was clearly and distinctly aware of it. It was an obvious truth that he could arrive at by thinking. It was the result of rational intuition. Due to the conclusion of the cogito, Descartes argued that whatever he perceived clearly and distinctly was true.

Answer 10

A clear idea is one that is bright and present to the mind. A distinct idea is a pure one that is sharply separated from other ideas. A clear and distinct idea is one that is the object of rational intuition. As such, clear and distinct ideas are indubitable. They are beyond rational doubt.

Answer 11

Not clear and distinct enough: Leibniz suggested that a more detailed account of clear and distinct ideas is required if they are to be used as a criterion of truth. Relying on a feeling is not enough. Descartes does not give us a clear and distinct account of what he means by clear and distinct

Answer 12

Hasty generalisation Because the success of the cogito is down to the fact that it could be grasped clearly and distinctly, Descartes claims that any belief that is clear and distinct will also (and necessarily) be true. But why must this be case? Consider the following: 1. The only man I have observed is rude 2. Therefore, all men are rude This is a hasty generalisation. Doesn’t Descartes’ reasoning follow a similarly faulty structure?

Answer 13

Only internal criteria of truth What makes a belief true or false is whether it corresponds to the external world, the world outside my mind. By using the criterion of ‘clear and distinct’ to establish the truth of a proposition, Descartes is ignoring its connection to the external world. 1. For a belief to be true we may have to consider two factors: 2. Its nature (whether it is clear and distinct). Whether it corresponds to the external world. Descartes only considers a).

Answer 14

Can we be sure that clear and distinct ideas are true? Descartes goes on to question whether clear and distinct are always true and decides that the only way he can know this is to prove that God exists. If God exists, then he wouldn’t make it be the case that our clear and distinct ideas were false. He then goes on prove that God exists. However, as we will see, Descartes uses his clear and distinct ideas to prove that God exists. This is circular! Descartes uses his clear and distinct ideas to prove that God exists so that he can prove that his clear and distinct ideas are reliable

Answer 15

Hume argues that the objects of enquiry or reason fall into two very distinct categories: relations of ideas and matters of fact. The two operate independently of one another. Relations of ideas can tell us nothing about matters of fact and vice versa. Descartes mistake is to claim that relations of ideas (his clear and distinct ideas, rational intuition and deduction) can provide information about the world itself. Humes fork

Answer 16

Descartes can successfully prove that he exists using only his reason, he has established a proposition that is synthetic a priori. He has shown that he has used reasoning (relations of ideas) to establish a truth about the world (matter of fact). The cogito is a priori intuition because: - It is not known through sense experience or empirical observation. - The truth that he exists is discovered by thinking and reasoning alone. - The cogito is an example of a rational intuition of the clear and distinct idea that he exists. - The cogito could also be viewed as a deduction that follows from the intuition that he is thinking. - If we assume that Descartes’ knowledge of his existence is a claim about the world, then the cogito is an example of synthetic a priori knowledge.

Answer 17

Criticism 1: different thinkers If Descartes can only be sure that he exists when he is actually thinking about it, perhaps he ceases to exist when he’s not thinking about it Criticism 2: no meaningful self - just a bundle of thoughts Hume claimed that when we look into ourselves to search for the self, we never find it. All we find is a ‘bundle’ of sensations: perceptions of various things. ‘I never can catch myself at anytime without a perception and never observe anything but the perception.’ The ‘I’ that Descartes believes exists appears to be nothing other than a collection of constantly changing perceptions. It is not the separate substance that Descartes claims it is. Criticism 3: radical doubts - no thinker at all Do thoughts even need a thinker? It might seem obvious that thoughts require a thinker, but is this something that is completely indubitable?

Answer 18

Criticism 1: the use of concepts/language Descartes draws on concepts like thought, doubt and existence. He might say that these are innate but in fact they are derived from experience. Descartes could respond by saying that this criticism misses the point. The cogito is proved/justified through reason; no experience is involved in this. Criticism 2: levels of certainty Most a priori knowledge is true for all time, not just at the time it is thought about. E.g. the proposition ‘a triangle has 3 sides’ is true always for all time. By contrast, a posteriori propositions are only true when a particular observation has taken place. E.g. ‘the grass is green’ is only true when the grass is green. Descartes’ conclusion ‘I exist’ appears only to be true when he thinks of it. This makes it very unlike other a priori propositions and perhaps more like an a posteriori proposition. Descartes could respond by saying that just because the cogito is only true when being thought of this does not make it similar to an a posteriori proposition. It is just a very unique type of a priori proposition.

Answer 19

If God exists, he would not allow Descartes’ clear and distinct ideas to be false. Descartes defines God as: ‘a substance that is infinite, eternal, unchangeable, independent, supremely intelligent and supremely powerful, which created myself and anything else that may exist’. Formally using the method of intuition and deduction P1: The cause of anything must at least be as perfect as its effect P2: My ideas but be cause by something P3: I am and imperfect being P4: I have the idea of God, which is that of a perfect being C1: I cannot be the cause for my idea of God C2: Only a perfect being can be the cause of my idea of God C3: God must exist

Answer 20

1. The principle of causation is not clear and distinct. We can think of instances when the effect of something does seem to be more ‘perfect’ than its cause. E.g. A match that lights a vast wildfire. A whisper that causes an avalanche. The principle of causation is not obviously and indubitably true. 2. The idea of God comes from experience; it is not innate. Hume said that the idea of God could come from experience. We see a good or powerful person and then imagine someone who is even better/more powerful. We keep augmenting this idea until we reach the idea of the perfect being. In this way, we can have a perfect idea that arises from a series of imperfections. This means we do not have an a priori intuition of God. It is derived a posteriori. 3. The principle of causation is not a priori; it comes to us through experience (a posteriori). Perhaps it is only by observing causes and effects in the world that the principle of causation can be known. If this is the case then Descartes’ idea is not an a priori intuition but is instead an a posteriori one. This means that Descartes’ proof is not an example of intuition and deduction. 4. Descartes’ idea of God is not universal. Other religions may not share the same idea of God. Certainly, ancient Greek gods were conceived in a very different way. If Descartes’ idea of God is not universal then it is not an idea that can be said to be obviously present in our minds. It is not clear and distinct. 5. We don’t understand what ‘infinite’ means. We might be able to express the idea in words but we cannot understand it properly. If we try to think of infinity, we may only be able to imagine it by thinking of what infinity isn’t: the finite. If this is correct then we cannot really have an idea of an infinite being and Descartes argument doesn’t work. Note also that this means that the idea of God as an infinite being is most definitely not clear and distinct!

Answer 21

In order to reach the conclusion that God exists, Descartes has relied on his clear and distinct ideas. However, he cannot rely on his clear and distinct ideas until he has proved that God exists. (Remember that God is required as the guarantor of his clear and distinct ideas). It seems then that Descartes needs to rely on his clear and distinct ideas in order to know that he can rely on his clear and distinct ideas! This is circular reasoning and is logically invalid.

Answer 22

Descartes asks if his own existence is enough to show that God exists. In order to do this, he asks where his own existence might have come from. Has Descartes created himself? No. Descartes would have depended on nothing else for his existence and would have made himself perfect. He would in fact be God. But he is clearly not God (think of the imperfections). Has Descartes always existed? No. Past existence is not a guarantee of present existence. Something must be conserving his existence (sustaining his existence). Descartes is not conserving his own existence so there must be something else doing this that is the ultimate explanation for his existence. Does Descartes’ existence derive from his parents? No. In an obvious sense, yes. But they didn’t create him out of nothing. They are responsible for the organisation of matter (not mind). They don’t conserve his existence and so can’t be the ultimate explanation for his existence. We would also need to explain his parents’ existence and this would end in an infinite regress Does Descartes’ existence derive from God? Yes. All the other causes have been rejected. The ultimate cause must be God. Although his physical substance came from his parents, his thinking substance must have come from another thinking substance.

Answer 23

Perhaps Descartes did create himself, and is responsible for conserving himself. It might just be the case that he is unaware of this. Perhaps Descartes was created by a less than perfect being, or by a process like evolution. After all, the options Descartes gives us (himself, God, parents) seem hardly exhaustive.

Answer 24

P1: I have an idea of God, that is to say, an idea of a perfect being. P2: A perfect being must have all the perfections. P3: Existence is a perfection. C: Therefore, God exists. An example of rational intuition and deduction at work. Descartes believes that by closely examining the idea of God - subjecting it to the light of reason - he can see its essential features. And just as he can see what the essential features of a triangle are (i.e. that the sum of the angles add to 180 degrees), so too can he see the essential features of God - his perfection and, therefore, his existence.

Answer 25

1. I have an idea of a perfect island 2. As a perfect island, the island must have all the perfections 3. Existence is a perfection Conclusion: The perfect island exists Obviously we cannot prove the existence of a perfect island this way and so there must be something wrong with Descartes’ reasoning. Descartes response There is a very important difference between the idea of a perfect island and that of a perfect being. To imagine that the island doesn’t exist does not entail a logical contradiction. The existence of the island is contingent. Descartes would claim that imagining the non-existence of God entails a contradiction. It would be like imagining a triangle with angles that don’t equal 180°, or a mountain without a valley. Existence is a necessary feature of God in a way that it isn’t with the island.

Answer 26

A predicate of something describes what that object is like e.g. it is tall, green, round. When we say that something ‘exists’ we are not adding anything to its description that would help us identify it. Existence refers to whether or not a concept has been actualised (i.e. whether or not it exists in reality), not to a property of the concept itself. (We can talk about a yellow car or a car that is not yellow, for example, where yellow is a property, but can we really meaningfully talk of the existing or non-existing car?) Existence cannot therefore be regarded as a predicate and is therefore not something that an object has. Descartes’ ontological argument works because existence is seen as a predicate of God. Because existence cannot be a predicate, ontological arguments cannot work.

Answer 27

Hume’s distinction between relations of ideas and matters of fact. All of Descartes’ arguments for the existence of God are a priori. That is, they are arguments involving relations of ideas. Hume is quite clear that this sort of reasoning can reveal nothing about the world itself. All it can do at best is reveal things about the meanings of the terms used. E.g. the ontological argument doesn't tell us that God exists. It simply tells us that contained within the idea of God is the idea of existence. Hume’s distinction between relations of ideas and matters of fact. All of Descartes’ arguments for the existence of God are a priori. That is, they are arguments involving relations of ideas. Hume is quite clear that this sort of reasoning can reveal nothing about the world itself. All it can do at best is reveal things about the meanings of the terms used. E.g. the ontological argument doesn't tell us that God exists. It simply tells us that contained within the idea of God is the idea of existence.

Answer 28

Descartes can imagine a triangle (visualise it his mind). He can also intellectually understand what a triangle is, i.e. it is a 3 sided shape. Descartes cannot really visualise a chiliagon (a 1000 sided figure) and if he were to do so, it wouldn’t look much different from a myriagon ( a 10000 sided figure) He could, however, intellectually understand what a chiliagon is, and differentiate it from a triangle or indeed any other shape. Descartes believes that this proves that the intellect and the imagination are two distinct faculties. The intellect is a core part of him. It allows him to prove that he exists (the cogito). The intellect uses a priori reasoning. The intellect is not dependent on anything outside of itself. If Descartes didn’t have the imagination, he would still be able to prove his own existence. Imagination is not, therefore, an essential part of him. Because the imagination is not part of Descartes it must depend on some object other than himself. Perhaps then the imagination is what happens when he turns his mind to the body and apprehends the information that comes through the senses. The intellect requires no sensory input and deals with a priori reasoning. This is just a suggestion, but it is certainly plausible, and would allow for the possibility of a body outside of Descartes’ mind.

Answer 29

Step 1: Descartes wishes to demonstrate that sensations come from outside of him and provides two separate arguments for this. Step 1a P1: The will (my free will) is a part of my essence. P2: Sensation is not subject to my will C: Therefore, sensations come from outside of me. Step 1b P1: My nature or essence is unextended (my mind doesn’t take up any space). P2: Sensations are ideas of extended things (things that take up space). C: Therefore, sensations come from outside of me.

Answer 30

Step 2 P1: There are two possible sources for the origin of sensation: God or matter P2: I have a strong natural inclination to believe they come from matter, and I have no faculty by which to correct this belief. C1: So if their origin were in God, Gould would be a deceiver. P3: God is not a deceiver. C2: Therefore, sensation originates in matter. The external material world exists.

Answer 31

Problem with step 1a Descartes claims that sensations must come from outside of him because they happen against his will. However, we sometimes have sensations that are against our will and yet do come from within ourselves. Dreams are a good example of these. Perhaps then sensations do actually come from Descartes, only from a part of him that is unconscious.

Answer 32

Problem with step 1b Perhaps an unextended thing can have extended ideas. It is not clear and distinct that this could never be the case. Problem with step 2, premise 3 Would God really not deceive us? Perhaps there are times when deception ought to take place. General problem with step 2 Perhaps God doesn’t exist. It is far from certain that Descartes’ proofs of God’s existence have been successful.

Answer 33

First ‘wave’ of doubt: Descartes doubts whether his senses are deceiving him or not. After all, they have deceived him in the past. Second ‘wave’ of doubt: Descartes doubts whether he is awake. Perhaps he is dreaming and everything he perceives is simply part of a dream. Third ‘wave’ of doubt: Descartes supposes that there is an evil demon who wishes to deceive him and who produces all these experiences in him. If this were true, he wouldn’t be able to be certain of anything! Descartes arrives at global scepticism: We can not be certain of any knowledge we have. We cannot know anything. This is doubt without limit.