George Berkeley 
Three Dialogues Between Hylas and Philonous in Opposition to Sceptics and Atheists [EPUB ebook] 

‘Three Dialogues between Hylas and Philonous’ is a book written by George Berkeley in 1713.
Three important concepts discussed in the Three Dialogues are perceptual relativity, the conceivability/master argument, and Berkeley’s phenomenalism.
George Berkeley (12 March 1685 – 14 January 1753) — known as Bishop Berkeley (Bishop of Cloyne) — was an Anglo-Irish philosopher whose primary achievement was the advancement of a theory he called ‘immaterialism’ (later referred to as ‘subjective idealism’ by others).