The Corn Laws were not repealed before 1846. In the meantime, the British economy kept growing, a fact that effectively undermined the credibility and thrust of Ricardian economics in Britain; but Ricardo had by now established himself as the first stationary state theorist in the history of economic thought. Ricardo's preoccupation with class conflict anticipated the work of Karl Marx (see below). John Stuart Mill was the leading economist, philosopher and social reformer in mid-19th century Britain. His economics treatise on the "Principles of Political Economy", published in 1848, attained status as the standard textbook in economics throughout the English-speaking world until the turn of the century. A champion of classical liberalism, Mill believed that an ideal society should allow all individuals to pursue their own good without any interference from others or from government. Also a utilitarian philosopher, Mill regarded the 'Greatest Happiness Principle' as the ultimate ideal for a harmonious society:  Mill's concept of the stationary state was strongly coloured by these ideals. Mill conjectured that the stationary state of society was not too far away in the future:  Contrary to both Smith and Ricardo before him, Mill took an optimistic view on the future stationary state. Mill could not "... regard the stationary state of capital and wealth with the unaffected aversion so generally manifested toward it by political economists of the old school." Instead, Mill attributed many important qualities to this future state, he even believed the state would bring about "... a very considerable improvement on our present condition." According to Mill, the stationary state was at one and the same time inevitable, necessary and desirable: It was "inevitable", because the accumulation of capital would bring about a falling rate of profit that would diminish investment opportunities and hamper further accumulation; it was also "necessary", because mankind had to learn how to reduce its size and its level of consumption within the boundaries set by nature and by employment opportunities; finally, the stationary state was "desirable", as it would ease the introduction of public income redistibution schemes, create more equality and put an end to man's ruthless struggle to get by — instead, the human spirit would be liberated to the benefit of more elevated social and cultural activities, 'the graces of life'. Hence, Mill was able to express all of his liberal ideals for mankind through his concept of the stationary state. It has been argued that Mill essentially made a quality-of-life argument for the stationary state. When the influence of John Stuart Mill and his "Principles" declined, the classical-liberalist period of economic theorising came to an end.