George Berkeley (1685 – 1753) was a brilliant Anglo-Irish philosopher of the early modern period. One of his primary achievements was the advancement of idealism, the view that denies the existence of material substance. Berkeley defends that reality consists exclusively of minds and their ideas, like tables and chairs are only ideas in the minds of perceivers.
Berkeley is also known for his critique of abstraction which he considers illusionary and inaccessible. In this context, Berkeley is criticizing Locke who suggests that mind derives something common and alike in all particular objects, creating a new, abstract idea. Berkeley shows that it is impossible, for example, to form the abstract idea of motion distinct from the body moving, since it must neither be walking, nor flying, nor creeping. Likewise, we cannot frame to ourselves the abstract idea of body, for it must be either of a white, a black, a tawny, a crooked, a tall or a short man. Opposing abstract ideas, Berkeley suggests that we can frame to ourselves a general idea that represents or stands for all other particular ideas of the same sort. For instance, when we say “motion”, we consider any body in motion, whether it is flying, creeping or walking, that applies correctly to this general word.
