Yoga Sutra - IV - 20 - EKA SAMAYE COBHAYANAVADHARANAM - The mind-stuff cannot perceive both the subject and object simultaneously [which proves it is not self-luminous].Swami Satchidananda - "The mind-stuff perceives objects outside. At other times, if is is clean enough, it can turn within and reflect the Purusha also. So, it can be either subject or object. As subject, it see other things. As an object, it is seen by the Purusha. But the Purusha can never be both. It is always the subject."
"How to Know God - The Yoga Aphorisms of Patanjali" translated and commented on by Swami Prabhavananda and Christopher Isherwood:
As we saw at the very beginning of this book (I, 2), the mind is not the seer, but the instrument of the Atman, which is eternally conscious. The mind is only intermittently conscious of objects, and its perceptions of them vary according to its own fluctuations. The mind is changing all the time, and so is the object of perception. The Atman alone, by remaining unchanged, provides a standard by which all perception can be measured.
We are given a partial quote from Swami Vivekananda that "Motion can only be perceived when there is something else which is not moving..."
We are given the statement - The mind is just as much an object of perception as any object it perceives in the external world. The mind is not self-luminous; that is to say, it is not a light-giver, like the sun, but a light-reflector, like the moon. The light-giver, the "sun," is the Atman, and the mind only shines and perceives by the reflected light of the Atman. The mind cannot perceive both itself and an external object simultaneously.




