CAUSE
465
CAUSE
that object, followed by another, "where, if the first
object had not been, tlte second would never have existed",
or "an abject followed by another, and whose appearance
alivays conveys the thought to that other" (ibid.). In
this doctrine Hume advances a psychological explana-
tion of the origin of the idea (habit), but inculcates
an utter scepticism as to the reality of causation.
Hume's position was sharply attacked by Thomas
Reid, who invoked "common sense" to confute him,
principally on account of the consequences of his scep-
ticism in the region of natural theology. But Reid,
mistaking the doctrine of the Schoolmen as to per-
ception — he supposed that Scholasticism taught that
the species sensibilis was that which is perceived,
rather than that by which the sensible object is per-
ceived — went so far as to assert that sense perception
is the same as intellectual judgment. Reid was ac-
cused by Kant of having altogether misunderstood
the point of the question raised by Hume; and was
defended by Galluppi, who instead makes Kant mis-
taken as to Hume's meaning. Kant represents Hume
as saying: "Metaphysical causation is not in the ob-
jects observed; therefore it is a product of the imagi-
nation based on custom or habit." This he alters to:
"Causation is not in the things observed; therefore
it is in the observer." But Hume's real argument is:
"Metaphysical causality is not in the things observed:
therefore it cannot be in the observer, in whom all
is derived from observation." This, he says, Reid
thoroughly understands, and pertinently retorts:
"As a matter of fact the concept of metaphysical
causation is in the intellect; and, since it is not de-
rived from the things observed, it must therefore be
a subjective law of the observer." Had Reid not
misunderstood the import of the species sensibilis his
appeal to "common sense" would have given him a
greater affinity to the Schoolmen. His division of
first principles as necessary or contingent has the
metaphysical in the first category. Among these he
places the principle of causation, thus assigning it a
place as a necessary first principle, prior to all experi-
ence and independent of it.
Thomas Brown, whose work was said by Mackin- tosh to be "an open revolt against the authority of Reid", agrees with Hume in resolving causality into invariable succession, but dissents from his theory that the idea has its origin in "habit", and contends, with Reid, that it is an intuitive, or first truth. His analysis of consciousness into "the whole series of states of the mind", and consequent denial that there is a consciousness capable of knowing its own states, is, however, in explicit contradiction with Reid's teaching. Thus, Reid having overlooked the point of transition from phenomenal observance to nou- menal truth, Brown still further separates the two and prepares the way for Hamilton ami Mill, the former of whom makes our notion of causality a be- lief dependent upon a powerlessness of our nature to think otherwise. The latter explains causality as uniform antecedence, the growth of human experi- ence, and not to be extended beyond the realm of experience. " In distant parts of the stellar regions", he writes, "where the phenomena may be entirely un- like those with which we are acquainted, it would be folly to affirm that this general law prevails." (Sys- tem of Logic, III, xxi.)
Hume was the philosophical predecessor of Kant. We accordingly find in the "Kritik der reinen \'er- nunft" that, on the question of causality, the doc- trine of Kant, to a considi rable extent, is in substan- tial agreement with that of the Scottish sceptic. Where Hume posited a repetition of similar instances of connexion, by the observance of which is set up a habit that accounts psychologically for the idea of necessary causation, Kant advances a regular succes- sion of effect from cause. This regular succession, whatever it may chance to be in nature, is physical III.— 30
causation. But we cannot know anything of it a
priori. There is, as far as we can discover, no reason
why A should succeed to B, rather than to C, D, or E.
Whatever the order of succession is de facto, we must
learn by observation, since there is nothing in the
nature of things, so far as we can judge, to make one
the consequent of another rather than of some third.
We do, however, know — and this a priori — that the
order of succession, whatever it may actually happen
to be, is, and must be, regular. This follows from a
fundamental position of the Kantian philosophy.
Space and time are a priori concepts, or subjective
forms. All phenomenal successions, whatever they
may be, exist in time and space. Or, rather, time is
regular succession, just as space is regular reciprocal
occupancy. Hence, whatever the things existing in
space may de facto be, and however the order of suc-
cession may happen to take place, the one must be
definitely determined to some set of reciprocal rela-
tions, and the other must be one, definite, and irrever-
sible. We arrive at a knowledge of the one actual
order of succession, of which some one order 7?>ust be,
by observation; but the datum of a regular order is
known beforehand. Efficient causality, therefore, in
the world, as regular succession, is an a priori item
of knowledge. What the precise order is remains to
be discovered, and its formulation is the formulation
of natural laws. Between cause, then, and effect
there is a constant and necessary relation; but the
effect is not in the cause. In the scheme of categories
developed by Kant, cause and effect fall under the
head of Relation, together with substance and acci-
dent, and action and passion. But the relation is
known through experience, and consequently is of no
value beyond the realm of experience. No inference
can be made from it to God, as cause. The cosmolog-
ical proof is thus rejected by Kant.
From Kant onwards the two lines of thought already noted become yet more clearly marked. Indeed the elements of both are to be found in his own writings. On the one hand, the idealistic develop- ment of philosophic thought reaches its expression in Hegel, Schopenhauer, etc. On the other, science, as such, limits itself more and more to purely mechanical concepts. The problems of causality are referred to the idealistic standpoint, or else are treated in terms of matter and motion, with no reference to the essences of the effects. With Hegel causality takes the form of the development of the Idea, as the Abso- lute in itself (on sich), through its manifestation as otherness (fiir sich), and back to identity (an und fur itch i. All that is, in the way of cause, is the working out, or unfolding, and coming back to itself, of the Absolute Idea. Being is becoming. The Hegelian notion of Being as essentially pure thought issues naturallv in a kind of inversion of the ordinary notion of causality; for, with Hegel, the notion of causality is causality itself. Although he opposed Hegel and his philosophy with great violence, the system of Schopen- hauer is not greatly dissimilar to this. Sehopenhauer substitutes Will for Idea. The world, and its pro- cesses, are the objectivized form of the Will. Hut. strictlv speaking, Will cannot be considered as cause and effect. Rather are these but t wo aspects of one and the same thing. Thus Schopenhauer (as does to some extent von Hartmann i reduces causality to the universal operation of a single ideal principle. Both attenuate the idea of it, Schopenhauer by his ext rcme doctrine of relativity, von Hartmann by his concep- tion of the all-oneness of the Unconscious. According to Schopenhauer, we call cause thai -late of objects which is followed by another state (i. e. the effect), on account of the principle of sufficient reason of becoming — prineipitim rationis sufficientis fiertdi. This last notion of causality, as mere sequence, but without any idealistic ground to account for it, is that which principally obtains in current science. A
