sense-data, or even that the sense-data are directly properties of the table. Thus a problem arises as to the relation of the sense-data to the real table, supposing there is such a thing.
The real table, if it exists, we will call a "physical object." Thus we have to consider the relation of sense-data to physical objects. The collection of all physical objects is called "matter." Thus our two questions may be re-stated as follows: (1) Is there any such thing as matter? (2) If so, what is its nature?
The philosopher who first brought prominently forward the reasons for regarding the immediate objects of our senses as not existing independently of us was Bishop Berkeley (1685–1753). His Three Dialogues between Hylas and Philonous, in Opposition to Sceptics and Atheists, undertake to prove that there is no such thing as matter at all, and that the world consists of nothing but minds and their ideas. Hylas has hitherto believed in matter, but he is no match for Philonous, who mercilessly drives him into
