Good and evil, what.
Things then are good or evil, only in reference to pleasure or pain.
That we call GOOD, which is apt to cause or increase pleasure, or diminish pain in us; or else to procure or preserve us the possession of any other good or absence of any evil.

And, on the contrary, we name that EVIL which is apt to produce or increase any pain, or diminish any pleasure in us: or else to procure us any evil, or deprive us of any good.

By pleasure and pain, I must be understood to mean of body or mind, as they are commonly distinguished; though in truth they be only different constitutions of the MIND, sometimes occasioned by disorder in the body, sometimes by thoughts of the mind.
3.

Our passions moved by Good and Evil.
Pleasure and pain and that which causes them,--good and evil, are the hinges on which our passions turn.

And if we reflect on ourselves, and observe how these, under various considerations, operate in us; what modifications or tempers of mind, what internal sensations (if I may so call them) they produce in us we may thence form to ourselves the ideas of our passions.
4.