I shall imagine I have done some service to Truth,
Peace, and Learning if, by any enlargement on this
Subject, I can make Men reflect on their own Use of
Language; and give them Reason to suspect, that
since it is frequent for others, it may also be possible
for them, to have sometimes very good and approved
Words in their Mouths, and Writings, with
very uncertain, little, or no signification. And therefore
it is not unreasonable for them to be wary herein
themselves, and not to be unwilling to have them examined
by others.

In a later chapter of the same book Locke would attend to wit under the rubric "Of the Abuse of Words," but he had in fact discussed it at some length before deciding to take language as his province. This earlier passage from book 2 ("Of Ideas") is the one Addison put into...