The knowledge of good and evil is nothing but the consciousness of pleasure and pain tied to our power of activity; idea and emotion are distinct only in conception.

By Baruch Spinoza, from Ethics

Key Arguments

  • We call things good or evil as they help or hinder our conatus by increasing or diminishing our power of activity; thus we call them good or evil insofar as we perceive pleasure or pain.
  • The idea necessarily follows from the pleasurable or painful emotion, and there is no real distinction between the idea and the emotion save in conception.

Source Quotes

VIII. The knowledge of good and evil is nothing else but the emotions of pleasure or pain, in so far as we are conscious thereof. Proof.—We call a thing good or evil, when it is of service or the reverse in preserving our being (IV.
The knowledge of good and evil is nothing else but the emotions of pleasure or pain, in so far as we are conscious thereof. Proof.—We call a thing good or evil, when it is of service or the reverse in preserving our being (IV. Deff. i. and ii.), that is (III. vii.), when it increases or diminishes, helps or hinders, our power of activity.
Thus, in so far as we perceive that a thing affects us with pleasure or pain, we call it good or evil; wherefore the knowledge of good and evil is nothing else but the idea of the pleasure or pain, which necessarily follows from that pleasurable or painful emotion (II. xxii.). But this idea is united to the emotion in the same way as mind is united to body (II. xxi.); that is, there is no real distinction between this idea and the emotion or idea of the modification of the body, save in conception only. Therefore the knowledge of good and evil is nothing else but the emotion, in so far as we are conscious thereof.

Key Concepts

  • The knowledge of good and evil is nothing else but the emotions of pleasure or pain, in so far as we are conscious thereof.
  • we call a thing good or evil, when it is of service or the reverse in preserving our being
  • But this idea is united to the emotion in the same way as mind is united to body (II. xxi.); that is, there is no real distinction between this idea and the emotion or idea of the modification of the body, save in conception only.

Context

Ethics, Part IV, Propositions, Prop. VIII (lines ~3119–3127): affective-cognitive account of moral knowledge