1. What does Hylas call the most extravagant opinion that ever entered into the mind of man?  Who holds this extravagant opinion?
2. What do Hylas and Philonous agree that sensible things are?
3. Hylas eventually gives up on the existence of the sensible things he calls secondary qualities, but tries to defend the existence of primary qualities.  What is the difference between primary and secondary qualities, and what are some examples?
4. What is a material substratum?
5. Sketch the argument that Philonous gives for the conclusion that there must be some other mind wherein sensible things exist, other than his own.
6. Does Philonous think that if I am not perceiving the world, then the world does not really exist?  Why or why not?