[1] While the Latin term itself originates in scholasticism, it reflects the Aristotelian view of man as a creature distinguished by a rational principle.
In the Nicomachean Ethics I.13, Aristotle states that the human being has a rational principle (Greek: λόγον ἔχον), on top of the nutritive life shared with plants, and the instinctual life shared with other animals, i. e., the ability to carry out rationally formulated projects.
[2] That capacity for deliberative imagination was equally singled out as man's defining feature in De anima III.11.
This definition has been influential in the field of philosophical anthropology, where it has been reprised by Gilbert Durand, and has been echoed in the naturalist description of man as the compulsive communicator.
Throughout a long life I have looked diligently for evidence in favour of this statement, but so far I have not had the good fortune to come across it.