“The professors of wisdom in Greece did pretend,”
says Francis Bacon, “to teach a universal Sapience....
And it is a matter of common discourse of the chain
of the sciences how they are linked together, insomuch
that the Grecians, who had terms at will, have fitted
it of a name of Circle Learning” (Valerius Terminus,
Ch. I, Works, VI, 43). The ideal of such a universal
knowledge has played a dominant role in the course
of European culture, both scientific and humanistic,
whether expressed in the educational requirements for
merely the Roman orator and architect or at its apogee
in the eighteenth-century Encyclopédie for the
enlightenment of a whole age. It is partly in relation
to this ideal that the more limited concept of the unity
of the exact sciences arises; partly, however, it arises
from the nature of science itself. In a science the search
for unity and for intelligibility are inseparable. It is
natural for this search to extend itself beyond the
confines of the individual science to all the sciences
taken together.
The main conception of the unity of the sciences
until the time of Kant can, for convenience of classifi-
cation, be considered in relation to the ways in which
the sciences were in general, following Aristotle, dis-
tinguished from one another: (1) by their principles
or logical foundations, (2) by their subject matters, and
(3) by their methods. Consequently there are concep-
tions of unity underlying the principles of the different
sciences, of unity with respect to their subject matters,
and of unity with respect to their methods. To these
we can add a fourth conception of unity with respect
to the end or ends of science.
