If the perception of one mind by another mind be postulated, we would have to assume an endless number of them, and the result would be confusion of memory.

From Sri Swami Satchidananda, The Yoga Sutras of Patanjali, Book IV, Sutra 21, Buckingham, Virginia: Integral Yoga Publications, 2007 (first published in 1978), p. 218.

Addendum (January 24, 2008)

Even if the perception of one mind by that same mind at a different time be postulated, we would have to assume an endless number of them, and the result would still be confusion of memory. For a mind at one time is not the same as that very mind at another time. Memory changes just as mind does, as well. But to ward of any possibility of memory confusion, I date my addenda with meticulous care nonetheless.