That everything has a real constitution, whereby it is what it is, and on which its sensible qualities depend, is past doubt: but I think it has been proved that this makes not the distinction of species as WE rank them, nor the boundaries of their names.
Secondly, this tacitly also insinuates, as if we had IDEAS of these proposed essences.

For to what purpose else is it, to inquire whether this or that thing have the real essence of the species man, if we did not suppose that there were such a specifick essence known?
Which yet is utterly false.

And therefore such application of names as would make them stand for ideas which we have not, must needs cause great disorder in discourses and reasonings about them, and be a great inconvenience in our communication by words.
22.VI.Sixthly, by proceeding upon the supposition that the WOrds we use have a certain and evident Signification which other men cannot but understand.
SIXTHLY, there remains yet another more general, though perhaps less observed, abuse of words; and that is, that men having by a long and familiar use annexed to them certain ideas, they are apt to imagine SO NEAR AND NECESSARY A CONNEXION BETWEEN THE NAMES AND SIGNIFICATION THEY USE THEM IN, that they forwardly suppose one cannot but understand what their meaning is; and therefore one ought to acquiesce in the words delivered, as if it were past doubt that, in the use of those common received sounds, the speaker and hearer had necessarily the same precise ideas.

Whence presuming, that when they have in discourse used any term, they have thereby, as it were, set before others the very thing they talked of.

And so likewise taking the words of others, as naturally standing for just what they themselves have been accustomed to apply them to, they never trouble themselves to explain their own, or understand clearly others' meaning.