Having taken ‘a complete course in political economy’ directed by James Mill in 1819, Mill published his first piece in the field of political economy, entitled
‘Exchangeable Value’, in December 1822 in the Traveller.50 One of the most important essays in political economy in his early years was ‘Definition of Political Economy’, in which he presented his view of the relationship between the science and art of political economy. In this essay, he stated that ‘Science takes cognizance of a phenomenon, and endeavours to discover its law; art proposes to itself an end, and looks out for means to effect it’.51 On this basis, he opposed the view that, ‘Political Economy is a science which teaches, or professes to teach, in what manner a nation may be made rich’, a view which he thought was represented by Adam Smith’s Wealth of Nations. Such a
consideration should be part of the art, rather than of the science.
Rules, therefore, for making a nation increase in wealth, are not a science, but they are the results of science. Political Economy does not instruct how to make a nation rich; but whoever would be qualified to judge of the means of making a nation rich, must first be a political economist.52
Another definition of political economy – ‘The science of the laws which regulate the production, distribution, and consumption of wealth’ – was insufficient, even though it did not confound science and art.53 The law of the production of wealth might be related both to such physical sciences as chemistry and geology, and to psychological science. The former were not the subject-matter of political economy. Furthermore, he found problems even in such definitions of political economy as, ‘The science which treats of the production and distribution of wealth, so far as they depend upon the laws of human nature’, and ‘The science relating the moral or psychological laws of the
50 JSM, ‘Exchangeable Value [1-2]’, CW, xxii, 3-6. In this article, he defended Ricardo and James Mill against the criticism by Robert Torrens.
51 JSM, ‘Definition’, CW, iv, 312.
52 Ibid. See also Smith (1976) i, 428.
53 JSM, ‘Definition’, CW, iv, 314.
production and distribution of wealth’.54 To his mind, political economy was not concerned with all the laws of the production and distribution of wealth, but only with a certain portion of them, namely those laws operating in what he termed the ‘social state’.
Accordingly, he concluded that political economy dealt with man ‘solely as a being who desires to possess wealth, and who is capable of judging of the comparative efficacy of means for obtaining that end’, and only with ‘such of the phenomena of the social state as take place in consequence of the pursuit of wealth’.55 He concluded, therefore, that the complete definition of political economy should be:
The science which traces the laws of such of the phenomena of society as arise from the combined operations of mankind for the production of wealth, in so far as those phenomena are not modified by the pursuit of any other object.56
Having defined political economy as a science, Mill developed his methodology. As early as 1828 he had written a review of Richard Whatley’s Elements of Logic, in which he agreed with Whatley that the method of political economy should be deductive and syllogistic.57 In the early 1830s, however, he came to abandon his earlier view that syllogism was of much use in moral science, including political economy, though he maintained his belief in the use of a deductive method in moral science.58 In ‘Definition of Political Economy’, he insisted that conclusions from such hypotheses ‘might be totally without foundation in fact’. In this sense, a science which employed the deductive method was an abstract science, and its conclusions were hypothetical.
Significantly, this did not mean that a deductive science was either imperfect or useless.
In his opinion,
Geometry presupposes an arbitrary definition of a line, “that which has length but not breadth.” Just in the same manner does Political Economy presuppose an arbitrary definition of man, as a being who invariably does that by which he may obtain the greatest amount of necessaries, conveniences, and luxuries, with the
54 Ibid., 318.
55 Ibid., 321.
56 Ibid., 323.
57 JSM, ‘Whately’s Elements of Logic’, CW, xi, 1-35.
58 See JSM, Autobiography, CW, i, 189. See also JSM, ‘Definition’, CW, iv, 309-39. By ‘the method à priori’, Mill meant ‘reasoning from an assumed hypothesis’. (ibid., 325.)
smallest quantity of labour and physical self-denial with which they can be obtained in the existing state of knowledge.59
In ‘Definition of Political Economy’, Mill also examined the role of verification in political economy. Verification had no place in scientific processes, but did have a place in the application of science; verification was a process in which a conclusion which had been reached from assumed premises was compared with what actually happened;
it was not a process intended to verify premises in themselves by reference to empirical facts. This was because what actually happened was motivated by many motives other than economic ones, while reasoning in political economy was based only on
hypothetical economic motives.60
ii
More detailed argument on the definition and method of political economy can be found in the Logic. Oscar Kubitz regards the sections on political economy in the Logic as a complete development of the argument in ‘Definition of Political Economy’. He bases his conclusion on the following facts. First, in the Logic, Mill quoted many passages from ‘Definition of Political Economy’; and second, he republished
‘Definition of Political Economy’ with only minor changes, as part of Essays on Some Unsettled Questions of Political Economy, in 1844, the year following the publication of the Logic.61 However, there were crucial differences between ‘Definition of Political Economy’ and the Logic. First, in the latter, unlike in ‘Definition of Political Economy’, he proposed the existence of more than one deductive method; he conceived two kinds of deductive method – the geometrical method and the physical method. Second, he introduced the operation of à posteriori verification into the deductive method.62
In Mill’s opinion, ‘the chemical or experimental method’ was identified with the method of Coleridge and Macaulay amongst others,63 while ‘the abstract or geometrical
59 JSM, ‘Definition’, ibid., 326.
60 Ibid., 323-4.
61 Kubitz (1932) 232.
62 Snyder (2006) 306.
63 In his Autobiography, Mill stated that Macaulay used this method in his argument against James Mill.
(JSM, Autobiography, CW, i, 196.) In the Logic, Mill identified the chemical method as that employed by
method’ was attributed to Hobbes and the Bentham school.64 On the one hand, the chemical or experimental method was unsuitable in the social sciences because of the impossibility of experiment in these sciences. Moreover, even in chemistry, the deductive, namely the non-experimental, method was actually used.65 On the other hand, the geometrical method was insufficient in the social sciences in that it did not take into account the existence of counteracting causes. According to Mill, ‘The
phenomena of society do not depend, in essentials, on any one agency or law of human nature, with only inconsiderable modifications from others.’66 He thought that Hobbes and the Benthamites were correct in thinking that the social sciences should be
deductive, but they were incorrect in building their theory on too narrow a notion of acting causes in society.
Having denied the suitability of both methods in the social sciences, Mill instead presented ‘the concrete deductive or physical method’ as the sole suitable method.67 This method consisted of three logical steps: induction, deduction, and verification. The first, inductive step used the experimental method in order to discover the laws of human action which jointly produced a certain sort of behaviour in a specific case. In the second, deductive step, the effect of the combination of causes which had been discovered in the first step was deductively ascertained. In the third and final step, the ascertained effect was verified. In the Logic, contrary to ‘Definition of Political Economy’, Mill incorporated verification into the scientific process.
Mill regarded political economy as a science which dealt with ‘one large class of social phenomena, in which the immediately determining causes are principally those which act through the desire of wealth; and in which the psychological law mainly concerned is the familiar one, that a greater gain is preferred to a smaller’. He went on to state:
By reasoning from that one law of human nature, and from the principal outward circumstances … which operate upon the human mind through that law, we may be
Coleridge and his followers. (JSM, Logic, CW, viii, 885.)
64 JSM, Logic, CW, viii, 888-94.
65 Ibid., 882, 886.
66 Ibid., 894.
67 See p. 98 above.
enabled to explain and predict this portion of the phenomena of society, so far as they depend on that class of circumstances only; overlooking the influence of any other of the circumstances of society; and therefore neither tracing back the
circumstances which we do take into account, to their possible origin in some other facts in the social state, nor making allowance for the manner in which any of those other circumstances may interfere with, and counteract or modify, the effect of the former.68
Whatever man’s actual motivations were, political economists were to assume that the preference for a greater gain to a smaller one was the sole motivation for his economic actions. Reasoning in political economy, therefore, should be based on this general hypothesis. As a result, its conclusions would inevitably be hypothetical, for, ‘They are grounded on some supposititious set of circumstances, and declare how some given cause will operate in those circumstances, supposing that no others are combined with them’.69 In this sense, political economy should be seen as a hypothetical science.
4. Beyond the Science of Political Economy