George Berkeley at 333

Yesterday was the 333rd anniversary of the birth of Irish philosopher George Berkeley (1685). I recently came across a very good essay on Berkeley and his philosophy by Ken Francis at New English Review. Berkeley is famous for his philosophical idealism. He believed that material substance is an illusion created by minds, that all that really exists are ideas in minds.

Francis begins by mentioning the Scottish clergyman Ronald Knox who sought to mock Berkeley's philosophy:

[T]he philosopher George Berkeley did not believe in the existence of the material world .... In fact, he did not believe in the physical existence of the entire universe for that matter (or should it be ‘non-matter’?). Knox’s limerick to Berkeley went something like this:

There was a young man who said God
Must find it exceedingly odd
To think that the tree
Should continue to be
When there’s no one around in the quad.

An anonymous reply to Knox’s limerick added:

Dear Sir, your astonishment’s odd;
I am always about in the quad
And that’s why the tree
Will continue to be
Since observed by yours faithfully, God.

There's much of interest in Francis' article which touches on other philosophers (Plato, Locke, Kant) besides Berkeley. He poses, for instance, this puzzle:

Are the words that you are now reading on this page, including the backdrop to wherever you are reading, part of the conceptualized reality of a Supreme Entity, of which our collective consciousness is a manifestation? Berkeley believes that every-day objects are such a manifestation with multiple visual aspects that can change depending upon the circumstances. This also brings into play the problem of appearance and reality.

Take for example a fingerprint. If asked to describe one, the obvious answer would be that it’s a small black blob, about two-inches in circumference, with whirly lines going through it. The philosopher Bertrand Russell would call this favouritism, as we tend to view objects from an ordinary point of view under usual conditions of light, but the other colours/shapes which appear under other conditions have just as good a right to be considered real.

In other words, if we look a little closer, through a powerful microscope, our conventional idea of what a fingerprint looks like takes on a whole new meaning. For here we see something that resembles a huge mountain range, a kind of dark grey version of the Himalayas.

And if we stand back from the fingerprint, say about 20 feet, it looks like a tiny black spot (without the whirly bits). The same applies to everything else we perceive—from tables and chairs to mountains and oceans. But we describe most everyday objects from the very convenient distance, usually a couple of feet away, of a human perceiver, with its meaning relative to how such a perceiver thinks.

So, is reality observer relative? Does what it's like depend upon how we perceive it? If so, then doesn't our perception actually in some sense establish the reality that something has?

These are fascinating questions. I encourage you to read Francis' entire article at the link, and don't forget to wish the Reverend Berkeley a happy 333rd.