48. The abstract ideas of substances always imperfect, and therefore various.
But this is not all. It would also
follow that the names of substances would not only have, as in truth they have, but would also be supposed to
have different significations, as used by different men, which would very much cumber the use of language. For if
every distinct quality that were discovered in any matter by any one were supposed to make a necessary part of
the complex idea signified by the common name given to it, it must follow, that men must suppose the same word
to signify different things in different men: since they cannot doubt but different men may have discovered
several qualities, in substances of the same denomination, which others know nothing of.