— 441 —
      §5.Thus if the Idea of Body, with some People, be bare Extension,
or Space, then Solidity is not essential to Body: If others make the
Idea, to which they give the name Body, to be Solidity and Exten-
sion, then Solidity is essential to Body. That therefore, and that alone
is considered as essential, which makes a part of the complex Idea the name
of a Sort stands for, without which, no particular Thing can be
reckoned of that Sort, nor be intituled to that name. Should there be
found a parcel of Matter, that had all the other Qualities that are in
Iron, but wanted Obedience to the Load-stone; and would neither
be drawn by it, nor receive Direction from it, Would any one ques-
tion, whether it wanted any thing essential? It would be absurd to
ask, Whether a thing really existing, wanted any thing essential to it.
Or could it be demanded, Whether this made an essential or specifick
difference, or no; since we have no other measure of essential or
specifick, but our abstract Ideas? And to talk of specifick Differences
in Nature, without reference to general Ideas and Names, is to talk
unintelligibly. For I would ask any one, What is sufficient to make
an essential difference in Nature, between any two particular Beings,
without any regard had to some abstract Idea, which is looked upon
as the Essence and Standard of a Species? All such Patterns and
Standards, being quite laid aside, particular Beings, considered
barely in themselves, will be found to have all their Qualities equally
— 442 —
essential; and every thing, in each Individual, will be essential to it,
or, which is more true, nothing at all. For though it may be reason-
able to ask, Whether obeying the Magnet, be essential to Iron? yet,
I think, it is very improper and insignificant to ask, Whether it
be essential to the particular parcel of Matter I cut my Pen with,
without considering it under the name Iron, or as being of a certain
Species? And if, as has been said, our abstract Ideas, which have names
annexed to them, are the Boundaries of Species, nothing can be
essential but what is contained in those Ideas.
Locke Hum III, 6, §5, pp. 441-442