The pamphlet was rewritten and enlarged,and a third edition of 1818gives a full exposition of his theory.Brown had meanwhile become Stewart's leading disciple,and in 1810was elected to be his colleague,Brown held the position,doing all the active duties,until his premature death in 1820.Brown,according to his biographer,wrote his lectures immediately before delivery,and completed them during his first two years of office.His theories,as well as his words,were often,acceding to the same authority,extemporised.
Brown found that he could not improve what he had written under 'very powerful excitement.'Moreover,he had an unlucky belief that he was a poet.From 1814till 1819he brought out yearly what he supposed to be a poem,these productions,the Paradise of Coquets and the rest,are in the old-fashioned taste,and have long passed into oblivion.
The lectures,published posthumously,became a textbook for students,and reached a nineteenth edition in 1851.
Their faults,considered as philosophical treatises,are palpable,they have the wordiness of hasty composition,and the discursive rhetoric intended to catch the attention of an indolent audience.Brown does not see that he is insulting his hearers when he apologises for introducing logic into lectures upon metaphysics,and indemnifies them by quotations from Akenside and the Essay on Man .Brown,however,showed great acuteness and originality.He made deviations,and took pains to mark his deviations,from Reid,though he spoke more guardedly of his own friend,Stewart,Stewart,who had strongly supported Brown's election,was shocked when,on the publication of the lectures,he came to discover that his colleague had been preaching heresy,and wrote with obvious annoyance of Brown's hastiness and dangerous concessions to the enemy.5Brown,however,impressed his contemporaries by his ability.Sydney Smith is probably reporting the current judgment of his own circle when he says 6that in metaphysics Stewart was a 'humbug'compared with Brown,I certainly think that Stewart,whom I should be sorry to call a humbug,shows less vigour and subtlety.Brown,at any rate,impressed both the Mills,and his relation to them is significant.
Brown's Essay upon Causation indicates this relation.In this,indeed,there is little,if any,divergence from Stewart,though he attacks Reid with considerable asperity.He urges that Reid,while really agreeing with Hume,affected to answer him under cover of merely verbal distinctions.7The main point is simple.
Hume had asserted that all events seem to be 'entirely loose and separate,'or,in other words,'conjoined but never connected.'Yet he points out that,in fact,when we have found two events to be 'conjoined,'we call one cause and the other effect,and assume a 'necessary connection'between them.He then asks,What is the origin of this belief,and what,therefore,is the logical warrant for its validity?Brown entirely accepts Hume's statement of the facts.The real meaning of our statements is evaded by 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,8this 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.9Could 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.'10Brown especially argues against the attempts of d'Alembert and Euler to deduce the first laws of motion from the principle of 'sufficient reason.'11That,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,12that '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 determining,independently of experience,any particular event.