y appealing to the conception of 'power.'
When the loadstone (in his favourite illustration) attracts the iron,
we say it has a 'power' of attracting iron. But to speak thus of a
power is simply to describe the same facts in other words. We assert
this, and nothing more than this, that when the loadstone comes near
the iron, each moves towards the other. 'Power' is a word which only
covers a statement of 'invariable antecedence.' Brown traces the
various confusions which have obscured the true nature of this belief.
He insists especially that we can no more discover power in mental
than in physical sequences. The will had been supposed to be the type
of causal power; but volition, according to Brown, reveals simply
another succession of desires and bodily actions. The hypothesis of
'power' has been really the source of 'illusion.' The tendency to
personify leads us to convert metaphor into fact, to invent a subject
of this imaginary 'power,' and thus to create a mythology of beings to
carry on the processes of nature. In other words, Brown here follows
Hume or even anticipates Comte. As J. S. Mill remarks,[471] this
erroneous identification of 'power' with 'will' gives the
'psychological rationale of Comte's great historical generalisation';
and, so far, Brown, as a follower of Hume, is clearly on the way to
positivism.

The world, then, is a vast aggregate of 'loose' phenomena. A
contemplation of things reveals no reason for one order rather than
another. You may look at your loadstone as long as you please, but you
will find no reason for its attracting iron. You may indeed
interpolate a number of minute intervening sequences, and the process
often suggests a vague something more than sequence; but this is a
mere illusion.[472] Could we, in fact, see all the minute changes in
bodies we should actually perceive that cause means nothing but 'the
immediate invariable antecedence of an event.'[473] Brown especially
argues against the attempts of d'Alembert and Euler to deduce the
first laws of motion from the principle of 'sufficient reason.'[474]
That, as he argues in detail, is merely begging the question, by
introducing the principle of causation under an alias.

What, then, is the principle? We believe, he says,[475] that 'every
event must have a cause,' and that circumstances exactly 'similar must
have results exactly similar.' This belief, though applicable to all
events, does not give us the 'slightest aid' to de