ensome to idle
people, is the employing ourselves in the pursuit of knowledge. I
remember Mr. Boyle, speaking of a certain mineral, tells us that a man
may consume his whole life in the study of it without arriving at the
knowledge of all its qualities. The truth of it is, there is not a
single science, or any branch of it, that might not furnish a man with
business for life, though it were much longer than it is.

I shall not here engage on those beaten subjects of the usefulness of
knowledge, nor of the pleasure and perfection it gives the mind, nor on
the methods of attaining it, nor recommend any particular branch of it;
all which have been the topics of many other writers; but shall indulge
myself in a speculation that is more uncommon, and may therefore,
perhaps, be more entertaining.

I have before shown how the unemployed parts of life appear long and
tedious, and shall here endeavour to show how those parts of life which
are exercised in study, reading, and the pursuits of knowledge, are long,
but not tedious, and by that means discover a method of lengthening our
lives, and at the same time of turning all the parts of them to our
advantage.

Mr. Locke observes, "That we get the idea of time or duration, by
reflecting on that train of ideas which succeed one another in our minds:
that, for this reason, when we sleep soundly without dreaming, we have no
perception of time, or the length of it whilst we sleep; and that the
moment wherein we leave off to think, till the moment we begin to think
again, seems to have no distance." To which the author adds, "and so I
doubt not but it would be to a waking man, if it were possible for him to
keep only one idea in his mind, without variation and the succession of
others; and we see that one who fixes his thoughts very intently on one
thing, so as to take but little notice of the succession of ideas that
pass in his mind whilst he is taken up with that earnest contemplation,
lets slip out of his account a good part of that duration, and thinks
that time shorter than it is."

We might carry this thought further, and consider a man as on one side,
shortening his time by thinking on nothing, or but a few things; so, on
the other, as lengthening it, by employing his thoughts on many subjects,
or by entertaining a quick and constant succession of ideas. Accordingly,
Monsieur Malebranche, in his "Inquiry after Truth," which was published
several years before Mr. Locke'