Passage 1:
Reliable definition:
- Truth and advantage are linked
- something must explicitly explain why truth and advantage are linked
Evolution selects what is advantageous to us, and gives us faculties to view the world in ways that are advantageous to us - not nessarily true, So, it is unclear to us that our faculties could be tracking the truth.
We could possibly explain this by saying:
- Truth explains advantage
- Advantage explains truth
- There is common ground between the two
Passage 2:
Moral facts have an essential normative aspect, but it is not clear that the normative aspect assists in any of the explanatory force. So, why can’t all moral facts be reduced to non-moral facts?
Take the example of a demonic fact, that being possesed means acting erratically and having ties to a demonic figure. If you lack either of these in your definition of demonic, then if you say that the behavior of being possesed is this incomplete fact, you are not explaining the full situtation in full. Some explanatory power is lost.
This is similar to if you neglect to include the normative component of morality.
Passage 3:
- Either Motive internalism or Motive externalism is true
- There exists a hitman that believes in moral facts but does not feel motivated by them
- Thus motive internalism is false and motive externalism is true
Kagan defends by saying that the hitman is using scare quotes, or the hitman lacks the proper faculties