common notions

Let us consider, then, the way in which one passes from the second kind [of knowledge] to the third. In the Ethics, everything becomes clear in this regard: the second and third kind of knowledge are systems of adequate ideas, but very different from one another. Ideas of the third kind are ideas of essences, inner essences of substance constituted by the attributes, and singular essences of modes involved in the attributes; and the third kind goes from essence to essence.
Deleuze – Spinoza: Practical Philosophy, p. 117

The common notions are more biological than mathematical.
De common notions (algemene begrippen) zijn  het gezichtspunt waaruit de Ethica geschreven is. De common notions vormen de overgang van de tweede naar de derde soort van kennis, we gaan voorbij het verstand en komen in het intuïtieve intellekt als systeem van essentiële waarheden of bewustzijn.

We ervaren de essentie.