e continue to regard
theologically; these are the ones which we do not yet understand how to
calculate, as the changes of the weather or the spread of epidemics. Which
science first attained the positive state, and in what order have the
others followed? With this criterion Comte constructs his _classification
of the sciences_, in which, however, he takes account only of those
sciences which he calls abstract, that is, those which treat of "events" in
distinction from "objects." The abstract sciences (as biology) investigate
the most general laws of nature, valid for all phenomena, from which the
particular phenomena which experience presents to us cannot be deduced, but
on the basis of which an entirely different world were also possible. The
concrete sciences, on the other hand (_e.g._, botany and zooelogy), have to
do with the actually given combinations of phenomena. The former follow out
each separate one of the general laws through all its possible modes of
operation, the latter consider only the combination of laws given in an
object. Thus oaks and squirrels are the result of very many laws, inasmuch
as organisms are dependent not only on biological, but also on physical,
chemical, and mathematical laws.

Comte enumerates six of these abstract sciences, and arranges them in such
a way that each depends on the truths of the preceding, and adds to these
its own special truths, while the first (the most general and simplest)
presupposes no earlier laws whatever, but is presupposed by all the
later ones. According to this principle of increasing particularity and
complexity the following scale results: (i) Mathematics, in which the
science of number, as being absolutely without presuppositions, precedes
geometry and mechanics; (2) Astronomy; (3) Physics (with five subordinate
divisions, in which the first place belongs to the theory of weight, and
the last to electrology, while the theory of heat, acoustics, and optics
are intermediate); (4) Chemistry; (5) Biology or physiology; (6) Sociology
or the science of society. This sequence, which is determined by the
increasing complexity and increasing dependence of the objects of the
sciences, is the order in which they have historically developed--before
the special laws of the more complicated sciences can be ascertained, the
general laws of the more simple ones must be accurately known. It is also
advisable to follow this same order of increasing complexity and difficult