"Know thyself" was the call to those seeking higher experiences, dating back to ancient Greece. The confrontation with oneself is the gateway to any knowledge that transcends one's own perspective. Whether one speaks of the doppelgänger, the guardian of the threshold, or one's own shadow, self-knowledge is among the deepest and most profound experiences of the inner journey. The editor has curated a selection of texts on this topic that reveals a meaningful sequence and makes the light and shadow aspects of the inner path meditatively comprehensible.