(as by the shape and figure in things of known seminal
propagation, and in other substances, for the most part by colour,
joined with some other sensible qualities,) do well enough to design the
things men would be understood to speak of: and so they usually
conceive well enough the substances meant by the word gold or apple, to
distinguish the one from the other. But in PHILOSOPHICAL inquiries and
debates, where general truths are to be established, and consequences
drawn from positions laid down, there the precise signification of the
names of substances will be found not only not to be well established
but also very hard to be so. For example: he that shall make
malleability, or a certain degree of fixedness, a part of his complex
idea of gold, may make propositions concerning gold, and draw
consequences from them, that will truly and clearly follow from gold,
taken in such a signification: but yet such as another man can never
be forced to admit, nor be convinced of their truth, who makes not
malleableness, or the same degree of fixedness, part of that complex
idea that the name gold, in his use of it, stands for.

16. Instance, Liquor.

This is a natural and almost unavoidable imperfection in almost all the
names of substances, in all languages whatsoever, which men will easily
find when, once passing from confused or loose notions, they come to
more strict and close inquiries. For then they will be convinced how
doubtful and obscure those words are in their signification, which in
ordinary use appeared very clear and determined. I was once in a meeting
of very learned and ingenious physicians, where by chance there arose a
question, whether any liquor passed through the filaments of the nerves.
The debate having been managed a good while, by variety of arguments on
both sides, I (who had been used to suspect, that the greatest part
of disputes were more about the signification of words than a real
difference in the conception of things) desired, that, before they went
any further on in this dispute, they would first examine and establish
amongst them, what the word LIQUOR signified. They at first were a
little surprised at the proposal; and had they been persons less
ingenious, they might perhaps have taken it for a very frivolous or
extravagant one: since there was no one there that thought not himself
to understand very perfectly what the word liquor stood for; which I
think, too, none of the most perplexed n