4. Useful to know the extent of our comprehension.
If by this inquiry into the nature of the understanding, I can
discover the powers thereof; how far they reach; to what things they are in any degree proportionate; and where
they fail us, I suppose it may be of use to prevail with the busy mind of man to be more cautious in meddling with
things exceeding its comprehension; to stop when it is at the utmost extent of its tether; and to sit down in a quiet
ignorance of those things which, upon examination, are found to be beyond the reach of our capacities. We should
not then perhaps be so forward, out of an affectation of an universal knowledge, to raise questions, and perplex
ourselves and others with disputes about things to which our understandings are not suited; and of which we
cannot frame in our minds any clear or distinct perceptions, or whereof (as it has perhaps too often happened) we
have not any notions at all. If we can find out how far the understanding can extend its view; how far it has
faculties to attain certainty; and in what cases it can only judge and guess, we may learn to content ourselves with
what is attainable by us in this state.
