This paper explores the notion of sensing (Empfinden) as developed by Erwin Straus. It argues that the notion of sensing is at the center of Strauss's thought about animal and human experience. Straus's originality consists in approaching sensory experience from an existential point of view. Sensing is not a mode of knowing. Sensing is distinguished from perceiving but is still a mode of relation to exteriority, and is situated on the side of what is usually called affectivity. At the same time Strauss redefines the field of that which is commonly characterized as affectivity. Sensing designates a stratum that lies deeper than the division between perceiving and feeling (s'éprouver), a self-affection that is not an alternative to the opening upon exteriority. It corresponds to a mode of immediate communication, to a sympathy with the world that does not entail any thematic dimension, but does not fall back into a blind fusion. Rather, sensing is something in the living being's mode of moving that is irreducible, and that includes a tending toward something.