A scientist is no more a collector and classifier of facts than a historian is a man who complies and classifies a chronology of the dates of great battles and major discoveries.

To understand a science it is necessary to know its history.

[H]istorical science is not worse, more restricted, or less capable of achieving firm conclusions because experiment, prediction, and subsumption under invariant laws of nature do not represent its usual working methods. The sciences of history use a different mode of explanation, rooted in the comparative and observational richness in our data. We cannot see a past event directly, but science is usually based on inference, not unvarnished observation (you don't see electrons, gravity, or black holes either).

Historical studies of the sciences tend to adopt one of two rather divergent points of view. One of these typically looks at historical developments in a discipline from the inside. It is apt to take for granted many of the presuppositions that are currently popular among members of the discipline and hence tends to view the past in terms of gradual progress toward a better present. The second point of view does not adopt its framework of issues and presuppositions from the field that is the object of study but tends nowadays to rely heavily on questions and concepts derived from studies in the history, philosophy, and sociology of science. A history written from the insider's point of view always conveys a strong sense of being "our" history. That is not the case with the second type of history, whose tone is apt to be less celebratory and more critical.

I fully agree with you about the significance and educational value of methodology as well as history and philosophy of science. So many people today - and even professional scientists - seem to me like somebody who has seen thousands of trees but has never seen a forest. A knowledge of the historic and philosophical background gives that kind of independence from prejudices of his generation from which most scientists are suffering. This independence created by philosophical insight is - in my opinion - the mark of distinction between a mere artisan or specialist and a real seeker after truth.
[Correspondance to Robert Thorton in 1944]

Scientists, social scientists and historians are all engaged in different branches of the same study: the study of man and his environment, of the effects of man on his environment and of his environment on man. The object of the study is the same: to increase man’s understanding of, and mastery over, his environment. The presuppositions and the methods of the physicist, the geologist, the psychologist and the historian differ widely in detail; nor do I wish to commit myself to the proposition that, in order to be more scientific, the historian must follow more closely the methods of physical science. But historian and physical scientist are united in the fundamental purpose of seeking to explain, and in the fundamental procedure of question and answer.

It is the historical mind, rather than the scientific (in the physicist's sense), that destroyed the mythical orientation of European culture; the historian, not the mathematician, introduced the "higher criticism," the standard of actual fact. It is he who is the real apostle of the realistic age. Science builds its structure of hypothetical "elements" and laws of their behavior, touching on reality at crucial points.[…] But the historian does not locate known facts in a hypothetical, general pattern of processes; his aim is to link fact to fact, one unique knowable event to another individual one that begot it.

More attention to the History of Science is needed, as much by scientists as by historians, and especially by biologists, and this should mean a deliberate attempt to understand the thoughts of the great masters of the past, to see in what circumstances or intellectual milieu their ideas were formed, where they took the wrong turning or stopped short on the right track.

Sciences are differentiated according to the various means through which knowledge is obtained. For the astronomer and the physicist both may prove the same conclusion: that the earth, for instance, is round: the astronomer by means of mathematics (i.e. abstracting from matter), but the physicist by means of matter itself. Hence there is no reason why those things which may be learned from philosophical science, so far as they can be known by natural reason, may not also be taught us by another science so far as they fall within revelation. Hence theology included in sacred doctrine differs in kind from that theology which is part of philosophy. SECOND ARTICLE [I, Q.

The historian (and for that matter the philosopher) is not God, looking at the world from above and outside. He is a man, and a man of his own time and place. He looks at the past from the point of view of the present: he looks at other countries and civilizations from the point of view of his own. This point of view is valid only for him and people situated like him, but for him it is valid. He must stand firm in it, because it is the only one accessible to him, and unless he has a point of view he can see nothing at all.

The man who thinks like a scientist seeks not only to note the facts, but also to analyze them taking into account their chance or their necessity, he tries to analyze the laws that immediate observation does not discern and to 'eliminate the influence of one's own inclinations on the results of one's reflections. 35

It is not what the man of science believes that distinguishes him, but how and why he believes it. His beliefs are tentative, not dogmatic; they are based on evidence, not on authority or intuition.

...to you, differences are quite unimportant; to me, they are what matters most. I am a scholar by nature; science is my vocation. And science is, to quote your words, nothing but the 'determination to establish differences.' Its essence couldn't be defined more accurately. For us, the men of science, nothing is as important as the establishment of differences; science is the art of differentiation. Discovering in every man that which distinguishes him from others is to know him.

The first fundamental rule of historical science and research, when by these is sought a knowledge of the general destinies of mankind, is to keep these, and every object connected with them, steadily in view, without losing ourselves in the details of special inquiries and particular facts, for the multitude and variety of these subjects is absolutely boundless; and on the ocean of historical science the main subject easily vanishes from the eye. ...In the higher grades of academic instruction, the lessons on history must vary with each one's calling and pursuits ...[T]he archives of many a state would alone furnish occupation for more than a man's life. ...The first fundamental rule ...to keep the attention fixed on the main subject, and not to let it be distracted or dissipated by a number of minute details—concerned more the method of historical science. The second rule regards the subject and purport of history... [W]e should not wish to explain every thing. Historical tradition must never be abandoned in the —otherwise we lose all firm ground and footing... [W]e have nothing to do but to record, as it is given, the best and safest testimony which tradition, so far as we have it, can afford... Extremely hazardous is the desire to explain every thing, and to supply whatever appears a gap in history—for in this propensity lies the first cause and germ of all those violent and arbitrary hypotheses which perplex and pervert the science of history far more than the open avowal of our ignorance, or the uncertainty of our knowledge: hypotheses which give an oblique direction, or an exaggerated and false extension to a view of the subject originally not incorrect. And even if there are points which appear not very clear to us, or which we leave unexplained—this will not prevent us from comprehending, so far... as the limited conception of man is able, the great outline of human history, though here and there a gap should remain.