Full Idea
We understand the things of which we are aware only when we have distinct ideas of them accompanied by the power to reflect and to derive necessary truths from those ideas.
Gist of Idea
We understand things when they are distinct, and we can derive necessities from them
Source
Gottfried Leibniz (New Essays on Human Understanding [1704], 2.21)
Book Reference
Leibniz,Gottfried: 'New Essays on Human Understanding', ed/tr. Remnant/Bennett [CUP 1996], p.173
A Reaction
A rather startling way of putting it, but we also say that good understanding brings the power to predict. What must you understand in order to predict? What has to happen next!