not indeed wanting in the world
compendiums of science, but many were written at a time when philosophy
was imperfect, as that of G. Valla; many contain only naked schemes, or
synoptical tables, as that of Stierius; and others are too large and
voluminous, as that of Alstedius; and, what is not to be considered as
the least objection, they are generally in a language, which, to boys,
is more difficult than the subject; and it is too hard a task to be
condemned to learn a new science in an unknown tongue. As in life, so in
study, it is dangerous to do more things than one at a time; and the
mind is not to be harassed with unnecessary obstructions, in a way, of
which the natural and unavoidable asperity is such as too frequently
produces despair.

If the language, however, had been the only objection to any of the
volumes already extant, the schools might have been supplied at a small
expense by a translation; but none could be found that was not so
defective, redundant, or erroneous, as to be of more danger than use. It
was necessary then to examine, whether upon every single science there
was not some treatise written for the use of scholars, which might be
adapted to this design, so that a collection might be made from
different authors, without the necessity of writing new systems. This
search was not wholly without success; for two authors were found, whose
performances might be admitted with little alteration. But so widely
does this plan differ from all others, so much has the state of many
kinds of learning been changed, or so unfortunately have they hitherto
been cultivated, that none of the other subjects were explained in such
a manner as was now required; and, therefore, neither care nor expense
has been spared to obtain new lights, and procure to this book the merit
of an original.

With what judgment the design has been formed, and with what skill it
has been executed, the learned world is now to determine. But before
sentence shall pass, it is proper to explain more fully what has been
intended, that censure may not be incurred by the omission of that which
the original plan did not comprehend; to declare more particularly who
they are to whose instructions these treatises pretend, that a charge of
arrogance and presumption may be obviated; to lay down the reasons which
directed the choice of the several subjects; and to explain more
minutely the manner in which each particular part of these volumes is to