Selection from – Ethics – Part V. On the Power of the Intellect; or of Human Freedom (Page 9)
Spinoza's Words: (of the third kind of knowledge)
Proposition XXIV. The more we understand particular things, the more do we understand (Deus xive Natura).
Proposition XXV. The highest endeavour of the mind, and the highest virtue is to understand things by the third kind of knowledge.
The third kind of knowledge proceeds from an adequate idea of certain attributes of (Deus sive Natura) to an adequate knowledge of the essence of things; and as we understand things more in this way, we better understand (Deus sive Natura); therefore the highest endeavour of the mind, is to understand things by the third kind of knowledge.
Proposition XXVI. In proportion as the mind is more capable of understanding things by the third kind of knowledge, it desires more to understand things by that kind.
Comment:
I am glad to regain my sympathy with Spinoza's thought. The first proposition above is obviously true.
Knowledge of the first kind is imagination or opinion and may be unverified; of the second kind is reason which may be verified but is subject to error and correction. Knowledge of the third kind is the insight that proceeds from "adequate knowledge." "Adequate knowledge" for Spinoza means complete understanding; something that is then absolutely true. Surely it is right that complete understanding should be "the highest endeavor of the mind."
Proposition XXVI states that adequate knowledge of something opens the mind to new questions and so it seeks for new answers, new knowledge. This agrees with Carl Sagan's dictum that "knowledge is mankind's destiny."