In this chapter we embark on a search for the individual with its triple identity, generic, singular and subjective, who lives with its double. We will see how protozoans transform into metazoans, then into meta-organisms, how “I is another”. Finally, we will see how a seventeenth century philosopher can help us understand such an entity as a whole made up of parts in a world of which it is a part, which acts and suffers, which is affected by some and which affects others while persisting in its being.