Listen, then:-- You know that men speak of human beings, taken singly, as individuals.
It is taken for granted in the common speech that the individual is the unit of humanity, not to be subdivided.

That is, indeed, what the etymology of the word means.

Nevertheless, the slightest reflection will cause any one to see that this assumption is a most mistaken one.

The individual is no more the unit of humanity than is the tribe or family; but, like them, is a collective noun, and stands for a number of distinct persons, related one to another in a particular way, and having certain features of resemblance.

The persons composing a family are related both collaterally and by succession or descent, while the persons composing an individual are related by succession only.