31. Extent of human knowledge in respect to its universality.
Hitherto we have examined the extent of our
knowledge, in respect of the several sorts of beings that are. There is another extent of it, in respect of
universality, which will also deserve to be considered; and in this regard, our knowledge follows the nature of our
ideas. If the ideas are abstract, whose agreement or disagreement we perceive, our knowledge is universal. For
what is known of such general ideas, will be true of every particular thing in whom that essence, i.e., that abstract
idea, is to be found: and what is once known of such ideas, will be perpetually and for ever true. So that as to all
general knowledge we must search and find it only in our minds; and it is only the examining of our own ideas
that furnisheth us with that. Truths belonging to essences of things (that is, to abstract ideas) are eternal; and are to
be found out by the contemplation only of those essences: as the existence of things is to be known only from
experience. But having more to say of this in the chapters where I shall speak of general and real knowledge, this
may here suffice as to the universality of our knowledge in general.