“Art is a mystery.
A mystery is something immeasurable.
In so far as every child and woman and man may be immeasurable, art is the mystery of every man and woman and child. In so far as a human being is an artist, skies and mountains and oceans and thunderbolts and butterflies are immeasurable; and art is every mystery of nature.”

Source: 1916 -1920, Autobiography', 1918, p. 17

P 118
The Piano Teacher (1988)

Ch 2
Man in Evolution (1941)

The Diary of Samuel Marchbanks (1947)
Context: But I wonder if people do not attach too much importance to the first-name habit? Every man and woman is a mystery, built like those Chinese puzzles which consist of one box inside another, so that ten or twelve boxes have to be opened before the final solution is found. Not more than two or three people have ever penetrated beyond my outside box, and there are not many people whom I have explored further; if anyone imagines that being on first-name terms with somebody magically strips away all the boxes and reveals the inner treasure he still has a great deal to learn about human nature. There are people, of course, who consist only of one box, and that a cardboard carton, containing nothing at all.

McKenna interview (1992)
Context: I love child things because there's so much mystery when you're a child. When you're a child, something as simple as a tree doesn't make sense. You see it in the distance and it looks small, but as you go closer, it seems to grow — you haven't got a handle on the rules when you're a child. We think we understand the rules when we become adults but what we really experienced is a narrowing of the imagination.

On Being a Real Person (1943)
Context: Every human life involves an unfathomable mystery, for man is the riddle of the universe, and the riddle of man is his endowment with personal capacities. The stars are not so strange as the mind that studies them, analyzes their light, and measures their distances.

Introduction.
Magick Book IV : Liber ABA, Part III : Magick in Theory and Practice (1929)
Context: This book is for
ALL:
for every man, woman, and child.
My former work has been misunderstood, and its scope limited, by my use of technical terms. It has attracted only too many dilettanti and eccentrics, weaklings seeking in "Magic" an escape from reality. I myself was first consciously drawn to the subject in this way. And it has repelled only too many scientific and practical minds, such as I most designed to influence.
But
MAGICK
is for
ALL.

Source: Dictionary of Burning Words of Brilliant Writers (1895), P. 421.

Arts http://www.hicsuntleones.co.uk/2007/06/arts.html, Hic Sunt Leones, 15/6/2007