Summary

Hylas worries that Philonous’s principles contradict Christianity. For example, if all ideas are in God, does this mean that pain and other imperfections are in God too? Philonous answers by giving an account of how bodies can exist as ideas, ending by saying that we feel pain only in virtue of our senses. While God has an idea of pain, it is not communicated to God by senses, and so he does not feel it.

Similarly, Hylas wonders whether Philonous can explain scientific principles like gravity. Science, Philonous assures Hylas, can still appeal to features like extension and solidity, since we perceive those things. Only the mysterious underlying matter is off bounds, but since that is unperceivable, we do not need it to explain reality. Philonous lays out the broad purpose of science on his account: to explain the...