Then a man (with opened spiritual eyes) not only senses the impressions of the physical and life world, but he beholds the sensations themselves. The sensation world of another being is spread out before a man with such an organ like an external reality. One must distinguish between experiencing one’s own sensation world, and looking at the sensation world of another person. Every man, of course, can see into his own sensation world. Only the seer with the opened spiritual eye can see the sensation world of another. Unless a man is a seer, he knows the world of sensation only as an inner one, only as the peculiar hidden experiences of his own soul. With the opened spiritual eye there shines out before the outward-turned spiritual gaze what otherwise lives only in the inner nature of another being.
In order to prevent misunderstanding, it may be expressly stated here that the seer does not experience in himself what the other being experiences as the content of his world of sensation. The other being experiences the sensations in question from the point of view of his own inner nature. The seer, however, becomes aware of a manifestation or expression of the sentient world.
Source: Rudolf Steiner – GA 9 – Theosophy: Chapter 1: The Essential Mature of Man: 4. Body, Soul and Spirit
Translated by Henry B. Monges and revised for this edition by Gilbert Church, Ph.D.