George Berkeley was an Anglo-Irish philosopher whose primary achievement was the advancement of a theory he called immaterialism, later referred to as subjective idealism. Immaterialism denies the existence of material substance and instead contends that familiar objects like tables and chairs are ideas perceived by the minds and, as a result, cannot exist without being perceived. George Berkeley is known for his critique of abstraction, an important premise in his argument for immaterialism. While living in London's Saville Street, George Berkeley took part in efforts to create a home for the city's abandoned children. The Foundling Hospital was founded by Royal Charter in 1739, and George Berkeley is listed as one of its original governors.
The philosophy of David Hume concerning causality and objectivity is an elaboration of another aspect of Berkeley's philosophy. A.A. Luce, the most eminent Berkeley scholar of the 20th century, constantly stressed the continuity of Berkeley's philosophy. The fact that Berkeley returned to his major works throughout his life, issuing revised editions with only minor changes, also counts against any theory that attributes to him a significant volte-face.
In 1709, George Berkeley published his first major work,
An Essay Towards a New Theory of Vision, in which he discussed the limitations
of human vision and advanced the theory that the proper objects of sight are not
material objects, but light and colour.
George Berkeley argued against Isaac Newton's doctrine of absolute space, time and motion in De Motu, published 1721. His arguments were a precursor to the views of Mach and Einstein. In 1732, he published Alciphron, a Christian apologetic against the free-thinkers, and in 1734, he published The Analyst, a critique of the foundations of calculus, which was influential in the development of mathematics.
Interest in George Berkeley's work
increased after World War II because he tackled many of the issues of paramount
interest to philosophy in the 20th century, such as the problems of perception,
the difference between primary and secondary qualities, and the importance of
George Berkeley believed that God is not the distant engineer of Newtonian machinery that in the fullness of time led to the growth of a tree in the university quadrangle. Rather, the perception of the tree is an idea that God's mind has produced in the mind, and the tree continues to exist in the quadrangle when "nobody" is there, simply because God is an infinite mind that perceives all.
The use of the concepts of "spirit" and "idea" is central in
Berkeley's philosophy. These concepts are difficult to translate into modern
terminology. His concept of "spirit" is close to the concept of "conscious
subject" or of "mind", and the concept of "idea" is close to the concept of
"sensation" or "state of mind" or "conscious experience".
George Berkeley denied the existence of matter as a metaphysical substance, but did not deny the existence of physical objects such as apples or mountains:
"I do not argue against the existence of any one thing that we can apprehend, either by sense or reflection. That the things I see with mine eyes and touch with my hands do exist, really exist, I make not the least question. The only thing whose existence we deny, is that which philosophers call matter or corporeal substance. And in doing of this, there is no damage done to the rest of mankind, who, I dare say, will never miss it."