An answer given by Mill's champion, to which Macaulay replies in his last article, suggests some explanation of Mill's position. Macaulay had paid no attention to one highly important phrase. The terrible consequences which Mill deduces from the selfishness of rulers will follow, he says, 'if nothing checks.'[109] Supplying this qualification, as implied throughout, we may give a better meaning to Mill's argument. A simple observation of experience is insufficient. The phenomena are too complex; governments of the most varying kinds have shown the same faults; and governments of the same kind have shown them in the most various degrees. Therefore the method which Macaulay suggests is inapplicable. We should reason about government, says Macaulay,[110] as Bacon told us to reason about heat. Find all the circumstances in which hot bodies agree, and you will determine the principle of heat. Find all the circumstances in which good governments agree, and you will find the principles of good government. Certainly; but the process, as Macaulay admits, would be a long one. Rather, it would be endless. What 'circumstances' can be the same in all good governments in all times and places? Mill held in substance, that we could lay down certain broad principles about human nature, the existence of which is of course known from 'experience', and by showing how they would work, if restrained by no distinct checks, obtain certain useful conclusions. Mill indicates this line of reply in his own attack upon Mackintosh.[111] There he explains that what he really meant was to set forth a principle recognised by Berkeley, Hume, Blackstone, and, especially, in Plato's _Republic_. Plato's treatise is a development of the principle that 'identity of interests affords the only security for good government.' Without such identity of interest, said Plato, the guardians of the flock become wolves. Hume[112] had given a pithy expression of the same view in the maxim 'established,' as he says, 'by political writers,' that in framing the 'checks and controls of the constitution, every man ought to be supposed a knave and to have no other end in his actions than private interest.' Mill points this by referring to the 'organs of aristocratical opinion' for the last fifty years. The incessant appeal has been for 'confidence in public men,' and confidence is another name for scope for misrule.[113] This, he explains, was what he meant by the statement (which Mackintosh considered to have been exploded by Macaulay) that every man pursued his own interest.[114] It referred to the class legislation of the great aristocratic ring: kings, nobles, church, law, and army. Utilitarianism, in its political relations, was one continuous warfare against these sinister 'interests,' The master-evil of the contemporary political state undoubtedly implied a want of responsibility. A political trust was habitually confounded with private property. Moreover, whatever else may be essential to good government, one essential is a strong sense of responsibility in the governors. That is a very sound principle, though not an axiom from which all political science can be deduced. If the essay on 'Government' was really meant as a kind of political Euclid--as a deduction of the best system of government from this single principle of responsibility--it was as grotesque as Macaulay asserted. Mill might perhaps have met the criticism by lowering his claims as his son suggests. He certainly managed to express his argument in such terms that it has an uncomfortable appearance of being intended for a scientific exposition.