considering it as wrong. This indispensable part
of Positive Philosophy he not only left to be supplied by others, but
did all that depended on him to discourage them from attempting it.

This hiatus in M. Comte's system is not unconnected with a defect in his
original conception of the subject matter of scientific investigation,
which has been generally noticed, for it lies on the surface, and is
more apt to be exaggerated than overlooked. It is often said of him that
he rejects the study of causes. This is not, in the correct acceptation,
true, for it is only questions of ultimate origin, and of Efficient as
distinguished from what are called Physical causes, that he rejects. The
causes that he regards as inaccessible are causes which are not
themselves phaenomena. Like other people he admits the study of causes,
in every sense in which one physical fact can be the cause of another.
But he has an objection to the _word_ cause; he will only consent to
speak of Laws of Succession: and depriving himself of the use of a word
which has a Positive meaning, he misses the meaning it expresses. He
sees no difference between such generalizations as Kepler's laws, and
such as the theory of gravitation. He fails to perceive the real
distinction between the laws of succession and coexistence which
thinkers of a different school call Laws of Phaenomena, and those of
what they call the action of Causes: the former exemplified by the
succession of day and night, the latter by the earth's rotation which
causes it. The succession of day and night is as much an invariable
sequence, as the alternate exposure of opposite sides of the earth to
the sun. Yet day and night are not the causes of one another; why?
Because their sequence, though invariable in our experience, is not
unconditionally so: those facts only succeed each other, provided that
the presence and absence of the sun succeed each other, and if this
alternation were to cease, we might have either day or night unfollowed
by one another. There are thus two kinds of uniformities of succession,
the one unconditional, the other conditional on the first: laws of
causation, and other successions dependent on those laws. All ultimate
laws are laws of causation, and the only universal law beyond the pale
of mathematics is the law of universal causation, namely, that every
phaenomenon has a phaenomenal cause; has some phaenomenon other than
itself, or some combination of phaenomena, on w