After ages of error, after wandering in all the mazes of vague and defective theories, writers upon politics and the law of nations at length arrived at the knowledge of the true rights of man, which they deduced from this simple principle: that he is a being endowed with sensation, capable of reasoning upon and understanding his interests, and of acquiring moral ideas.

They saw that the maintenance of his rights was the only object of political union, and that the perfection of the social art consisted in preserving them with the most entire equality, and in their fullest extent. They perceived that the means of securing the rights of the individual, consisting of general rules to be laid down in every community, the power of choosing these means, and determining these rules, could vest only in the majority of the community: and that for this reason, as it is imposible for any individual in this choice to follow the dictates of his own understanding, without subjecting that of others, the will of the majority is the only principle which can be followed by all, without infringing, upon the common equality.

Each individual may enter into a previous engagement to comply with the will of the majority, which by this engagement becomes unanimity; he can however bind nobody but himself, nor can he bind himself except so far as the majority shall not violate his individual rights, after having recognised them.

Such are at once the rights of the majority over individuals, and the limits of these rights; such is the origin of that unanimity, which renders the engagement of the majority binding upon all; a bond that ceases to operate when, by the change of individuals, this species of unanimity ceases to exist. There are objects, no doubt, upon which the majority would pronounce perhaps oftener in favour of error and mischief, than in favour of truth and happiness; still the majority, and the majority only, can decide what are the objects which cannot properly be referred to its own decision; it can alone determine as to the individuals whose judgment it resolves to prefer to its own, and the method which these individuals are to pursue in the exercise of their judgment; in fine, it has also an indispensible authority of pronouncing whether the decisions of its officers have or have not wounded the rights of all.

From these simple principles men discovered the folly of former notions respecting the validity of contracts between a people and its magistrates, which it was supposed could only be annulled by mutual consent, or by a violation of the conditions by one of the parties; as well as of another opinion, less servile, but equally absurd, that would chain a people for ever to the provisions of a constitution when once established, as if the right of changing it were not the security of every other right, as if human institutions, necessarily defective, and capable of improvement as we become enlightened, were to be condemned to an eternal monotony. Accordingly the governors of nations saw themselves obliged to renounce that false and subtle policy, which, forgetting that all men derive from nature an equality of rights, would sometimes measure the extent of those which it might think proper to grant by the size of territory, the temperature of the climate, the national character, the wealth of the people, the state of commerce and industry; and sometimes cede them in unequal portions among the different classes of society, according to their birth, their fortune, or their profession, thereby creating contrary interests and jarring powers, in order afterwards to apply correctives, which, but for these institutions, would not be wanted, and which, after all, are inadequate to the end.

It was now no longer practicable to divide mankind into two species, one destined to govern, the other to obey, one to deceive, the other to be dupes: the doctrine was obliged universally to be acknowledged, that all have an equal right to be enlightened respecting their interests, to share in the acquisition of truth, and that no political authorities appointed by the people for the benefit of the people, can be entitled to retain them in ignorance and darkness.

The success of the paradigm... is at the start largely a promise of success ... Normal science consists in the actualization of that promise... Mopping up operations are what engage most scientists throughout their careers. They constitute what I am here calling normal science... That enterprise seems an attempt to force nature into the preformed and relatively inflexible box that the paradigm supplies. No part of the aim of normal science is to call forth new sorts of phenomena; indeed those that will not fit the box are often not seen at all. Nor do scientists normally aim to invent new theories, and they are often intolerant of those invented by others.

Scientific development depends in part on a process of non-incremental or revolutionary change. Some revolutions are large, like those associated with the names of Copernicus, Newton, or Darwin, but most are much smaller, like the discovery of oxygen or the planet Uranus. The usual prelude to changes of this sort is, I believed, the awareness of anomaly, of an occurrence or set of occurrences that does not fit existing ways of ordering phenomena. The changes that result therefore require 'putting on a different kind of thinking-cap', one that renders the anomalous lawlike but that, in the process, also transforms the order exhibited by some other phenomena, previously unproblematic.

Even more difficult to explain, than the breaking-up of a single mass into fragments, and the drifting apart of these blocks to form the foundations of the present-day continents, is the explanation of the original production of the single mass, or PANGAEA, by the concentration of the former holosphere of granitic sial into a hemisphere of compressed and crushed gneisses and schists. Creep and the effects of compression, due to shrinking or other causes, have been appealed to but this is hardly a satisfactory explanation. The earth could no more shrug itself out of its outer rock-shell unaided, than an animal could shrug itself out of its hide, or a man wriggle out of his skin, or even out of his closely buttoned coat, without assistance either of his own hands or those of others.

Scientific truth, like puristic truth, must come about by controversy. Personally this view is abhorrent to me. It seems to mean that scientific truth must transcend the individual, that the best hope of science lies in its greatest minds being often brilliantly and determinedly wrong, but in opposition, with some third, eclectically minded, middle-of-the-road nonentity seizing the prize while the great fight for it, running off with it, and sticking it into a textbook for sophomores written from no point of view and in defense of nothing whatsoever. I hate this view, for it is not dramatic and it is not fair; and yet I believe that it is the verdict of the history of science.