Abstract:
The perception of identity is a characteristic feature of experience. We identify, or think we identify, familiar objects, scenes, or people, and we speak of the identity of a chair, or refer to the well known habitué as an 'old identity'. Such perception, casual in ordinary life, becomes of importance in discovering the identity of a criminal and is recognized as a science in the identification of organisms.
This perception of identity is a study for the psychologist. It is a problem of stimulus and response, of association and memory. Here I am not concerned with the psychological, aspects of identification but with that idea of identity which recurs throughout a wide variety of patterns of speech and thought. An idea which shifts in meaning and significance and which forms an elusive thread in the texture of language and philosophy. In analyzing this idea, it will be useful to examine both the usages of language and the practice of science. I will move, therefore, from language to metaphysics, from the concrete to the abstract.
