HKB
Having laid down these premises concerning relation in general, I shall now proceed to show, in some instances, how all the ideas we have of relation are made up, as the others are, only of simple ideas; and that they all, how refined or remote from sense soever they seem, terminate at last in simple ideas. I shall begin with the most comprehensive relation, wherein all things that do, or can exist, are concerned, and that is the relation of CAUSE and EFFECT: the idea whereof, how derived from the two fountains of all our knowledge, sensation and reflection, I shall in the next place consider.