The creation of synthetic life forms raises the question of what we mean when we say that a synthetic cell is “alive.” This paper analyzes the problem of aliveness both as an epistemological question (how can we know?) and as a phenomenological question (how can we perceive?). It introduces basic concepts that can be used in a phenomenological analysis of the “givenness” of life and argues that aliveness can only be seen with reference to the experiences of the observer as him/herself living. Life is therefore inherently ambiguous. When perceiving other life forms, we are aware of our own life. In order to develop a concept of the “other life” of a synthetic bacterium, we need to be aware of projecting perceptual evidence of our own life onto that of other species. The concept of “other life” can address a very basic layer: seeing another life form’s being-in-the-world as (1) a center of its own spontaneity, (2) a particular way of being in time that can be described as duration, and (3) as a system of processes that contain their own sense as practices.