The principle of laissez-faire had arrived to harmonise individualism and socialism, and to make at one Hume's egoism with the greatest good of the greatest number.
The political philosopher could retire in favour of the business man - for the latter could attain the philosopher's summum bonum by just pursuing his own private profit.
The individualism of the political philosophers pointed to laissez-faire.
The divine or scientific harmony (as the case might be) between private interest and public advantage pointed to laissez-faire.
'Virtue', he says, 'is the doing good to mankind, in obedience to the will of God, and for the sake of everlasting happiness' - in this way bringing to a parity. There is no rational ground, he argued, for preferring the happiness of one individual, even oneself, to that of any other.
Hence the greatest happiness of the greatest number is the sole rational object of conduct - taking utility from Hume, but forgetting that sage man's corollary: 'Tis not contrary to reason to prefer the destruction of the whole world to the scratching of my finger.' 'Tis not contrary to reason for me to choose my total ruin to prevent the least uneasiness of an Indian, or person totally unknown to me ...
This was one of the contributions of the eighteenth century to the air we still breathe.
The purpose of promoting the individual was to depose the monarch and the church; the effect - through the new ethical significance attributed to contract - was to buttress property and prescriptions.
Yet some other ingredients were needed to complete the pudding.
First the corruption and incompetence of eighteenth-century government, many legacies of which survived into the nineteenth.