Ralph Kirkpatrick on Rhythm

From Ralph Kirkpatrick's biography of Domenico Scarlatti:

It must not be forgotten that the ear is not necessarily a mathematical instrument. What is important to the ear is not necessarily measurable in terms of the metronome: it is what sounds ordered and exact. Like the eye, the ear is constantly capable of being tricked. As visual impressions constantly have to be corrected to ensure their desired effect on the eye, straight lines altered into slight curves in order to appear straight, so aural impressions, constantly qualified by varying musical elements and by acoustical effects, frequently need adjustment to meet the terms of the ear. The ear does not demand literal exactness any more than the eye demands geometrical precision. It demands the impression of a constant and unchanging set of proportions and dimensions, even though they may frequently be at variance with the physical reality.

You can hear him demonstrate his ideas about rhythm here.