In considering the act of perception, Picasso always was amazed at the discrepancy between seeing an object and knowing it. Its superficial appearance was to him absurdly inadequate. Seeing is not enough, neither is the aid that the other senses can bring. There are other faculties of the mind which must be brought into play if perception is to lead to an understanding. It is somewhere at the point of junction between sensual perception and the deeper regions of the mind that there is a metaphorical inner eye that sees and feels emotionally. Through this eye of the imagination it is impossible to see, to understand and to love even without sight in the physical sense, and this inner seeing may be all the more intense when the windows on the outer world are closed.
Picasso, his life and work, Roland Penrose, third edition, pp 88-89.