Selection from - Ethics – Part II. On the Nature and Origin of the Mind (Page 9)

Spinoza's Words: (on the third kind of knowledge)

We must bear in mind, that general notions [of things] are not formed by all men in the same way, but vary in each individual...

It is thus not to be wondered at, that among philosophers, who seek to explain things in nature merely by the images formed of them, so many controversies should have arisen. From all that has been said it is clear, that we, in many cases, perceive and form our general notions:— (1.) From particular things represented to our intellect fragmentarily, confusedly, and without order through our senses. I have settled to call such perceptions by the name of knowledge from the mere suggestions of experience.

(2.) From symbols, e.g., from the fact of having read or heard certain words we remember things and form certain ideas concerning them, similar to those through which we imagine things. I shall call both these ways of regarding things knowledge of the first kind, opinion, or imagination.

(3.) From the fact that we have notions common to all men, and adequate ideas of the properties of things; this I call reason and knowledge of the second kind. Besides these two kinds of knowledge, there is, as I will hereafter show, a third kind of knowledge, which we will call intuition. This kind of knowledge proceeds from an adequate idea of the absolute essence of certain attributes of (Deus sive Natura) to the adequate knowledge of the essence of things.


Three kinds of knowledge – Firstly, from the experience of the senses and from symbols. Secondly, from reason. And thirdly from intuition that comes from "the adequate knowledge of the essence of things." The term 'adequate knowledge' as Spinoza uses it means knowledge that we know is absolutely true.

Spinoza says in the next proposition – "Knowledge of the first kind is the only source of falsity, knowledge of the second and third kinds are necessarily true."