March 12, 1685

George Berkeley (March 12, 1685 to January 14, 1753) ) the British idealist is famous for having said "to be is to be perceived", and this had enormous impact on 20th century analytic philosophy and its sucky subjectivism.

An OUP summary of the significance of this thinker starts this way:

'An Irish-born philosopher, Berkeley is best known for his contention that the physical world is nothing but a compilation of ideas. This is represented by his famous aphorism esse est percipi (“to be is to be perceived”).

'Born in Kilkenny, Berkeley studied at Trinity College in Dublin, graduating with his Master of Arts degree in 1707. In Berkeley’s early work, his focus was mostly on the natural world and mathematics; however, his move towards philosophy is marked with his first philosophical publication, An Essay towards a New Theory of Vision (1709). His philosophical work was somewhat controversial and his importance initially quite overlooked. Berkeley’s influence was scarcely recognized at Trinity College until W. A. Butler wrote about him in the Dublin University Magazine in 1836.

'Although most scholarly work has focused on Berkeley’s idealism and immaterialism in A Treatise Concerning the Principles of Human Knowledge and Three Dialogues between Hylas and Philonous, his work was not solely limited to metaphysics. Berkeley’s works on vision have influenced discussions of visual perception from the 1700s to the present. He also wrote on ethics, natural law, mathematics, physics, economics, and monetary theory. At his death he was already recognised as one of Ireland’s leading men of letters but it wasn’t until A. A. Luce’s and David Berman’s twentieth-century scholarship that Berkeley’s true impact was fully appreciated.'

A later compendium of his work includes a dialogue between Alciphron and others, (Alciphron: or, The minute philosopher, 1732), and this is what we quote:

'For a thing to be natural, for instance, to the mind of man, it must appear originally therein, it must be universally in all men, it must be invariably the same in all nations and ages. These limitations of original, universal, and invariable, exclude all those notions found in the human mind, which are the effect of custom and education. The case is the same with respect to all other species of beings. A cat,for example, hath a natural inclination to pursue a mouse, because it agrees with the forementioned marks. But if a cat be taught to play tricks, you will not say those tricks are natural. For the same reason if upon a plum-tree peaches and apricots are engrafted, nobody will say they are the natural growth of the plum-tree. '

This is enough for me. The picture we have here is of a mind where mental machinations are not natural. And in fact, men are quite willing to believe they have ideas that in fact they cannot account for. And while we may wonder about the tricks Berkeley's cats know, it is a lovely prospect to think that men and cats are alike in having a set of natural principles. One will follow a mouse, the other will, follow a God. The path of later philosophy consisted of dropping the red laser light of Berkeley's arguments, while relying on his spadework.

What modern philosophy planted in Berkeley's garden is hardly Berkeley's fault.