Noun

individual (plural individuals)

1. A person considered alone, rather than as belonging to a group of people.

   He is an unusual individual.

2. An object, be it a thing or an agent, as contrasted to a class.
   • 2006 Steven French, “Identity and Individuality in Quantum Theory”, in Stanford Encyclopedia of Philosophy:

     It is typically held that chairs, trees, rocks, people and many of the so-called ‘everyday’ objects we encounter can be regarded as individuals.

As commonly used, an individual is a person or any specific object in a collection. In the 15th century and earlier, and also today within the fields of statistics and metaphysics, individual means "indivisible", typically describing any numerically singular thing, but sometimes meaning "a person." (q.v. "The problem of proper names"). From the seventeenth century on, individual indicates separateness, as in individualism. Individuality is the state or quality of being an individual; a person separate from other persons and possessing his or her own needs, goals, and desires.

Descartes

In his statement Cogito ergo sum ("I think therefore I am"), René Descartes posits the notion the individual subject, distinct from the world around him or her. This is the most famous articulation of subject-object dualism (see subject-object problem) in the Western philosophical tradition.