"Whenever any material step in general knowledge has been made,—whenever any philosophical discovery arrests our attention;—some man or men came before us, who have possessed, in an eminent degree, a clearness of the ideas which belong to the subject in question, and who have applied such ideas in a vigorous and distinct manner to ascertained facts and exact observations. We shall never proceed through any considerable range of our narrative, without having occasion to remind the reader of this reflection."
"The effect of these researches has been, a persuasion, that we need not despair of seeing, even in our own time, a renovation of sound philosophy, directed by the light which the History of Science sheds. Such a reform, when its Epoch shall arrive, will not be the work of any single writer, but the result of the intellectual tendencies of the age."
"The completeness of historical view... consists, not in accumulating all the details of the cultivation of each science, but in marking clearly the larger features of its formation."
"The Epochs here marked out, are the cardinal points of scientific history."
"All who venture upon such tasks [as this work] must gather trust and encouragement from reflections like those by which their great forerunner prepared himself for his endeavours;—by recollecting that they are aiming to advance the best interests and privileges of man; and that they may expect all the best and wisest of men to join them in their aspirations and to aid them in their labours. "Concerning ourselves we speak not; but as touching the matter which we have in hand, this we ask;—that men deem it not to be the setting up of an Opinion, but the performing of a Work; and that they receive this as a certainty; that we are not laying the foundations of any sect or doctrine, but of the profit and dignity of mankind:—Furthermore, that being well disposed to what shall advantage themselves, and putting off factions and prejudices, they take common counsel with us, to the end that being by these our aids and appliances freed and defended from wanderings and impediments, they may lend their hands also to the labours which remain to be performed:—And yet, further, that they be of good hope; neither feign and imagine to themselves this our Reform as something of infinite dimension and beyond the grasp of mortal man, when, in truth, it is of infinite errour, the end and true limit; and is by no means unmindful of the condition of mortality and humanity, not confiding that such a thing can be carried to its perfect close in the space of one single age, but assigning it as a task to a succession of generations."
"A very important advantage would be gained, if any light could be thrown upon the modes of discovering truth, the powers that we possess for this end, and the points to which these may most profitably be applied."
"If there be branches of knowledge which regard Morals, or Politics, or the Fine Arts, and which may properly be called Inductive (an opinion which I by no means gainsay); still it must be allowed, I think, that the processes of collecting general truths from assemblages of special facts, and of ascending from propositions of a limited to those of a larger generality, which the term Induction peculiarly implies, have hitherto been far more clearly exhibited in the physical sciences which form the subject of the present work, than in those hyper physical sciences to which I have not extended my history."