ESSENCE

[L:67] "The complex concept of all essential components of a thing...is the essence", which consists of both primitive and constitutive characteristics (grounds of the essence) and attributes (consequents of the essence). [L:144] To attributes, Kant distinguishes a thing's "real essence", which contains "the first ground of possibility". Empirical concepts can only be nominally defined, which is given in terms of attributes and not constitutive characteristics (which are given in a real definition). In morality, Kant claims, real definitions must always be sought.

What a thing is. For Greek philosophy , it means substance (ousia), that which is not apparent but is the true reality about things what can be conceived, what is universal. In Plato , it is the Forms or Ideas (from the Noumena). A similar idea is used by Santayana, Husserl , Thomas Aquinas , Kierkegaard , Sartre, and Heidegger .