monad

Each monad has its own destiny, and it acts and moves entirely of its own accord.

From The New Yorker ● Aug. 29, 2016

There she found another "bantling of fate," whose Nordic features suggested that he was an atavism, or at least a primeval anachronism; in any case, a monad.

From Time Magazine Archive

The individual is thus a monad which is inwardly aware of its actuality—a genius which beholds itself.

From Hegel's Philosophy of Mind by Georg Wilhelm Friedrich Hegel

Then what aid do these similarities of structure afford to the theory, that all the higher organisms have been evolved by successive steps out of the lowest monad?

From A Theory of Creation: A Review of 'Vestiges of the Natural History of Creation' by Francis Bowen

Trivalent, trī′vā-lent, or triv′-, adj. equivalent in combining or displacing power to three monad atoms.—n.

From Chambers's Twentieth Century Dictionary (part 4 of 4: S-Z and supplements) by Various