Lectures Notes on Chapter 5, Sections 2-4,
in Velasquez, PHILOSOPHY,for PHIL 120 Spring 2002
May 2, 2002 Section 5.2
1. What is rationalism? (366) The view that reason, without the aid of the senses, is able to arrive a some knowledge, some undeniable truths. In other words, we can come to know some truths without using vision, hearing, taste, smell, or touch, just by reflecting on our own ideas or mental processes.
a priori knowledge? (366) Knowledge that we can gain independent of sense-experience. Typically, such knowledge is held to be necessarily true and not subject to doubt. One of the usual candidates for such knowledge is mathematical truth, e.g., that 1+1=2, and the laws of logic, e.g., if a particular thing exists, it either possess an specific attribute or it does not possess that attribute. If I exist, I am either sitting or I am not sitting.
Do all rationalists think that all knowledge is gained by reason alone? (367) Some of them think that some of our knowledge, e.g., whether there are robins in Bowling Green, or whether Gore or Bush is now President of the United States, is gained through sense experience. But all rationalists hold that some of our knowledge is gained by reason alone.
2. What was Rene Descartes vitally concerned with discovering? (370) Something he could hold as true beyond any doubt.
3. What did Descartes decide he could not doubt? (371) "I cannot doubt that I exist, and that I am a thinking thing."
(A powerful evil spirit might exist and he might deceive me into thinking I had a body when I did not, but even if he could deceive me about that, it would still follow that I existed as a conscious being; for to be deceived is to be conscious, a thinking thing.)
4. How does Descartes think he comes to grasp the essence of the wax? (371-72)
By the use of the mind alone, not through the senses. The point is that this body, the wax, can lose its color, its capacity to make a sound when tapped, its smell, and yet it still remains what it is. It can even lose its specific shape (when it is turned into liquid) and its definite boundaries (when it is turned into gas). Yet throughout it retains its essence as a body, understood as having the capacity to occupy space such that other bodies are excluded. It takes the mind, the conceptual power of the soul, to grasp this essence. This is not something, says Descartes, that any of the senses could perceive. (The senses grasp concrete qualities like color, smell, etc., not abstractions like capacity to occupy space.)
Does Descartes appeal to sense information in "proving" the existence of God? (372)
(1) Descartes discovers that he has in his mind an idea of a perfect God.
He says that
(2) this idea of a perfect God could not be caused by anything less perfect than a perfect being.
An imperfect being like himself could not simply cobble together the idea of a perfect being.
He concludes that:
(3) there must be a perfect being to plant such an idea in Him.Therefore (4) God exists.
Descartes then goes on to prove, without trusting his senses, that the material world exists. That is, he has a very compelling idea that the material world exists, but not that it is colored or noisy or tasty, rather that it is characterized in geometrical terms (grasped by the mind).
Before he proved the existence of God, the idea of this world could still have been an illusion created by the evil demon. But now he has proven a perfect being exists, he can trust his clear ideas about the external world. God, being perfect, is not a deceiver. God would not permit him to be deceived by such compelling ideas of an external world.
5. How does Plato think we know mathematical truths? (374-76) At least in the Meno, Plato appears to think that we know mathematical truths before we acquire our present bodies. We can discover them through the activity of a teacher who leads us to reason, step by step, to apparently new truths. But this process is really a kind of recollection.
This is not recollection of particular events that happened earlier in the present life or prior lives. It is recollection of general truths that we in some sense saw with our naked souls before we acquired the present body. Learning is really recollection. To have knowledge in the normal sense is nothing but the ability to recall, at will, what we directly saw prior to our present lives when we were not attached to our present bodies..
Section 5.3
1. What is empiricism? The view that all knowledge about the world comes form or is based on the senses.A posteriori knowledge? (378) knowledge stated in empirically verifiable statements, i.e., knowledge based on the experience of the senses, either mine or somebody elses.
2. To what does John Locke compare the mind (at birth)? A blank slate, or white paper void of all characters.
Is Locke an empiricist? (379) Yes. For Locke knowledge of the external world originates in sense perception.
3. What was Locke asserting about physical objects in relation to our sense perceptions? (382 near bottom) Physical objects are independent of our sense perceptions. The objects are one thing and our perceptions of them something else, even if the objects cause our perceptions.
4. For Locke, physical qualities are powers in things to produce ideas in our minds.
What are primary qualities? (382) These are essentially measurable properties of things, like length, area, volume, weight, and motion.
Secondary qualities? These are not obviously measurable properties of things, like color, sound, taste, smell, etc.
How do our ideas of these qualities relate to the things that produce these ideas? (382-83)
(The answer is not the same in both cases.) Our ideas of secondary qualities do not agree with or copy the characteristics of the object that produce them. Our ideas of primary qualities do represent or copy the characteristics of the object that produced them. The idea I have of the length of this table is indeed very much like the actual length of the table that is here, but the idea I have of brownness in the table does not reproduce anything that is actually "out there." My idea of brown, in my mind, is very different from the power in the table to produce the sensation of brown in a perceiver.
5. What is the main point of the "copy theory" held by Locke? Our ideas are like copies of the things we know, at least in the case of the primary qualities. Our ideas of external things can certify that things outside the mind exist and provide an accurate picture of those external things in some respects. (383)
What problems for the copy theory does Velasquez note? (384) Locke assumes that we are directly aware only of the ideas of things, that we never come in direct awareness of external things. How can we know, then, that our ideas in at least some cases agree with the external things of which they are ideas? It would seem we couldn't know this. How can I know that my ideas of the length of this table agree with this table as it is in itself? It would seem I couldn't.
6. What predicament does Barry Stroud argue we are in? Unless we are persuaded by Descartes' proof for the existence of God, and very few philosophers are, we are left with the following possibility: what we think we know about the external world could be but a dream. The sensations and thoughts in our mind might not represent any reality outside the mind. . . .
We could be in the position of someone waking up to find himself in a room full of television sets and trying to find out what is going on outside. For all he can know, whatever is producing the patterns he can see on the screens in front of him might be something other than the well-functioning cameras directed on to the passing show outside the room . . . those pictures will be of no help without some independent information . . . The problem of the external world is the problem of finding out, or knowing how we could find out,a bout the world around us if we were in that sort of predicament.Why is this a difficulty for strict empiricism? (390-91) Strict empiricism says that the only way we learn about the external world is through the senses, but our sensory ideas are just that, sensory ideas. We can never step outside our ideas to directly confront unsensed reality and try to see if it is similar to the ideas.Section 5.4
1. What is transcendental idealism? (393) It is the view that both reason and sense-experience play a role in knowing. What Velasquez does not tell us right away is that reason for Kant is not limited to analyzing ideas and drawing conclusions; it is a mental activity by which the mind imposes order upon what would otherwise be a chaotic jumble of sense-impressions.
2. What did David Hume say about our sensations? Our sensations, considered in themselves, flow through us in a chaotic and continuously changing stream. (We are not, strictly speaking aware of any enduring things, either material things or minds.) (Hume was an empiricist who became a skeptic more or less like Barry Stroud.) (395)
3. What is Immanuel Kant's "remarkable insight"? (395) The mind organizes its sensations into the objects we see around us.
4. What is the most important of the "twelve relationships" or categories? (396) Cause-Effect: All perceived events have causes.
5. What three things can we say "if Kant is right"? (396-97) 1) The word we see or experience around us is a world that our own mind constructs. 2) Cause and effect are always a part of the world as we perceive it. 3) The world we observe around us might not be the way the world really is in itself. (Kant speaks of the unknowable Thing in Itself, which stands behind the sensations that are available to us.)
6. Explain the distinction between the noumenal world and the phenomenal world in Kant's philosophy? (397) The phenomenal world is the world we are aware of; this is the world we construct out of the sensations that are present to our consciousness. The noumenal world consists of things we seem compelled to believe in, but which we can never know (because we lack sense-evidence of it). The noumenal world contains (1) the Ding an sich, which lies behind or beneath the sense-impressions that we receive; (2) the free will, of which we can never have a sense impression, although we have to believe in it in order to make sense of the moral life.
For Kant, the empiricists are right when they say that our knowledge depends upon our sensations. But the rationalists are right when they say we can know the basic laws that structure the world quite apart from any particular sense-data. We know, for example, that every event has a cause. But we know that because the mind interprets sense-data so that this is true.
7. For Kant, is space a reality independent of mind? Is time? (397) The answer to both of these questions is NO. Space, for Kant, is nothing other than a mental structure that the mind uses to order sensations, e.g., as alongside one another. Time is nothing but a mental structure that the mind uses to order sensations, e.g., in terms of before and after.
8. What fundamental assumption of (most) earlier philosophers does Kant reject? The objective world is independent of our mind.
What does he hold instead? (398) Kant assumed that the objective world was, in significant part, a creation of the mind.