In this lecture the pre-eminent scholar in Jewish mysticism, Gershom Scholem, speaks of the Kabbalistic doctrine of the tselem, the astral body. The word “tselem” first appears in Genesis 1:26 when God creates man and says “let us make man in our image (tselem) and in our likeness.” In Hebrew “tselem” means “plastic image” and describes the individual essence of each human being. It constitutes an independent entity mediating between body and spirit. In mystical experience, the tselem could manifest as the perception of one’s own double, which revealed the deepest spiritual essence within man. Professor Scholem retraces the historical development of the doctrine of the tselem in Jewish mysticism and tells us how it is related to the principle of individuation in man.