[Footnote 2: J. S. Mill: Essay on Liberty, chap. II.]
Every important step in human progress has been a variation from the normal or accustomed, something new. Most advances in science have been departures from older and accustomed ways of thinking. Through the permission and encouragement of individual variation in opinion we may discover in the first place that accepted beliefs are wrong. Galileo thought differently from the accepted Ptolemaic astronomy of his day, and the demonstration of his diverging belief proved the Ptolemaic astronomy to be wrong. The evolutionary theory, bitterly attacked in its day, replaced Cuvier's doctrine of the forms of life upon earth coming about through a series of successive catastrophes. Lyell, in the face of the whole scientific world of his day, insisted on the gradual and uniform development of the earth's surface. Half the scientific doctrines now accepted as axiomatic were bitterly denounced when they were first suggested by an inquiring minority.
Milton in his famous Areopagitica, an address to Parliament written in 1644, protesting against the censorship of printing, stressed the importance of permitting liberty for the securing and developing of new ideas:
What should ye do then, should ye suppress all this flowery crop of knowledge and new light sprung up and yet springing daily in this city? Should ye set an oligarchy of twenty engrossers [censors] over it, to bring a famine upon our minds again, when we shall know nothing but what is measured us by their bushel? ... That our hearts are now more capacious, our thoughts more erected to the search and expectation of greatest and exactest things, is the issue of your own virtue propagated in us; ye cannot suppress that unless ye reënforce an abrogated and merciless law.... Give me the liberty to know, to utter, and to argue freely according to conscience, above all liberties.[1]
[Footnote 1: Milton: Areopagitica.]
Even if the currently accepted doctrines prove to be true, there is, as Mill pointed out, a vast social utility in permitting the expression of contrary opinion though it be an error. New ideas, however extreme, "may and commonly do possess some portion of truth"; they bring to light and emphasize some aspect or point of view which prevailing theories fail to note. Thus the possible over-emphasis of certain contemporary writers on the socialization of man's life is a valuable corrective to the equal over-emphasis on individualism which was current among so many thinkers during the nineteenth century. The insistence with which present-day psychologists call our attention to the power of instinct, though it may possibly be over-emphasized, counterbalances that tendency exhibited by such earlier authors as Bentham to picture man as a purely rational being, whose every action was determined by sheer logic.
Finally, unless doctrines are subjected to criticism and inquiry, no matter how beneficial they are to society, they will become merely futile and empty formulæ with very little beyond a mechanical influence on people's lives. The maxims of conventional morality and religion which everybody believes and few practice are solemnly bandied about with little comprehension of their meaning and no tendency to act upon them. A belief becomes, as Mill pointed out, living, vital, and influential in the clash of controversy. Whether novel and dissenting doctrines are true or false, therefore, the encouragement of their expression provides vitality and variation without which progress is not possible.
The social appreciation of persons who display marked individual opinions varies in different ages toward the same individual. The martyr stoned to death by one generation becomes the hero and prophet of the next. One has but to look back at the contemporary vilification and ridicule to which Lincoln was subjected to find an illustration. Or, on a more monumental scale:
The event which took place on Calvary rather more than eighteen hundred years ago. The man who left on the memory of those who witnessed his life and conversation such an impression of his moral grandeur that eighteen subsequent centuries have done homage to him as the Almighty in person, was ignominiously put to death, as what? As a blasphemer.[1]
[Footnote 1: Mill: Essay on Liberty, chap. II.]