In Berkeley’s book Three Dialogue, Berkeley uses the conversations between two characters Hylas and Philonous to state his philosophy. They discuss what a skeptic is and who could be one. Skeptic is someone who doubts everything and does not believe in the physical world. “I said indeed, that a skeptic was one who doubted of everything; but I should have added, or who denies the reality and truth of things.” (123) I thought it was interesting because Berkeley believes Descartes was a skeptic but in reality he was just trying to prove the difference between someone who is real and someone who is not by being a skeptic but indeed Descartes was not a skeptic. Hylas is someone who believes in matter, who believes what he sees. Philonous is someone who believes what the mind states is believable or not. Philonous believes in common sense; after all he is the lover of mind. Hylas accuses Philonous of being a skeptic because he often doubts thing if they do not make sense mentally, but Philonous proves him wrong and then accuses Hylas of being the real skeptic. Philonous states that he believes in what the mind will accept and not something that the senses determine. If something is logical and his mind accepts it then he will believe it. Hylas believes in what he gets from his senses. Berkeley also talks about two types of qualities; the primary and secondary qualities. Hylas states, “Colours, sounds, tastes, in all those termed secondary qualities, have certainly no existence without a mind. But by this acknowledgement I must not be supposed to derogate anything from the reality of matter or external objects, seeing it is no more than several philosophers maintain, who nevertheless are the furthest imaginable from denying matter.” (137) In class we discussed what the secondary and primary qualities are. Primary qualities are solidity, size, weight, shape, and motion. Secondary qualities are color, heat/feel, sound, taste, smell. Primary qualities are modes of extension; they exist without a mind, and can be described mathematically or logically. On the other hand secondary qualities are those that exist in the mind, if not one’s mind then someone else’s mind, but always in the mind. They are caused by primary qualities; they are all ideas that exist in the mind. For example when something heavy drops like a pot it makes a loud sound, but if no one is there to experience it then did it really make a sound? We use our secondary qualities to experience our primary qualities. Sound is an idea that exists in the mind; it would not happen if no one was there to have it in their mind. Sound would not be there if no one was there to experience it there would just be vibrations caused by the waves. Berkeley uses this idea to prove God’s existence. That is no one is there to experience it then it means that there is no sound, but how could that be possible there must be a sound. In order for sound to actually be there, someone must have it in their mind, and no one is there then that means God must have it in his mind, therefore sounds exist in God’s mind and God exist.