ABSTRACT
This chapter provides an overview of some foundational aspects of identity, which aim at relating biological theories with philosophical contributions to the issue. The notion of identity is one of the most fundamental concepts in philosophy and logic, not to mention in the study of human cultures, while at the same time being one of the most intricate. The chapter begins with a short sketch of philosophical problems and continues with discussion of the two main reasons why individual identity is a problem in a naturalistic setting. It describes that the biological boundaries of the organism are not fixed, as epitomised in theories about the extended phenotype. The chapter also describes that the brain sciences suggest that the brain is not a systematically integrated unit, but a set of loosely integrated modules. It concludes with an evolutionary model of the individual, which later serves as a framework for the economics of identity.
