Lecture 3

Consciousness - Lecture 3
B.A. Philosophy of Mind


Mary, a brilliant scientist, knows all the physical truths about human beings. However, she has never seen anything that isn’t black, white or grey. One day she leaves her black and white room and sees a red rose.

The Knowledge Argument

1 - Mary knows all the physical truths about seeing red without ever having seen red.
2 - Mary comes to know something new about seeing red when she leaves the room - she learns what it’s like to see red.
3 - Therefore, not all the truths about seeing red are physical.
4 - Therefore, Physicalism is false.

Lewis’ Response

Mary gets new knowledge, but doesn’t learn a new truth. She gains know-how. She gains abilities. For example, she can now imagine and remember seeing something red.

A response:
Mary’s new knowledge involves representing the world a certain way. She articulates her new knowledge by saying “seeing red is like this”. Her knowledge has a truth evaluable content, so it is not just know-how. It is not like knowing how to bake or swim.

Crane’s response to The Knowledge Argument

The argument aims to refute the thesis that every truth about a kind of conscious experience is really a truth about a kind of physical state. What is a truth? If the argument is to work, they must obey this principle: If it’s possible to know truth A without knowing truth B, then A is not identical with B. But if truths obey this principle, it seems that no Physicalist would want to formulate their view in terms of truths. Consider Sarah, who knows all the physical truths about Sherwood Forest, but is lost. Then she learns a new truth: “Major Oak is over there”. Therefore not all truths about the forest are physical truths. The appropriate response is to formulate Physicalism as we have been doing: every kind of conscious experience is really a kind of physical state.