At any particular stage in the development of science, our concepts concerning the causal relationships will then be true only relative to a certain approximation and to certain conditions.

in science you are dealing with facts. You prove them or dispute them, not the complicated stories of wars that happened before we were born.

Current science is not only concerned with seeking the truth. His part of scientific spirit, which in no way resembles science as it is commonly conceived, is far from equaling that of an anti-scientific spirit hostile to the first, but apparently much more scientific than him. p.287

Science consists in grouping facts so that general laws or conclusions may be drawn from them.

Three stages of truth for scientists:

(1) It's not true.

(2) If it is true, it's not very important.

(3) We knew it all along.

There are two ways in which a science develops; in response to problems which is itself creates, and in response to problems that are forced on it from the outside.

In our talks upon evolution, as I mentioned in the first lecture, we have been dealing somewhat with suppositions, and concerning ourselves with possibilities. Certain things we do know, and certain truths have been ascertained; yet even the conclusions of science, for instance, such as were so much spoken of and insisted upon forty years ago, are no longer regarded as facts, and are not used or promulgated as drastically and as emphatically as they were. Science itself is finding every year that its knowledge is very relative.

Science is feasible when the variables are few and can be enumerated; when their combinations are distinct and clear. We are tending toward the condition of science and aspiring to do it. The artist works out his own formulas; the interest of science lies in the art of making science.

[T]he classification of facts and the formation of absolute judgments upon the basis of this classification—judgments independent of the idiosyncrasies of the individual mind—essentially sum up the aim and method of modern science. The scientific man has above all things to strive at self-elimination in his judgments, to provide an argument which is as true for each individual mind as for his own. The classification facts, the recognition of their sequence and relative significance is the function of science, and the habit of forming a judgment upon these facts unbiassed by personal feeling is characteristic of what may be termed the scientific frame of mind.

In our time of ever-increasing specialization, there is a tendency to concern ourselves with relatively narrow scientific problems. The broad foundations of our present-day scientific knowledge and its historical development tend to be forgotten too often. This is an unfortunate trend, not only because our horizon becomes rather limited and our perspective somewhat distorted, but also because there are many valuable lessons to be learned in looking back over the years during which the basic concepts and the fundamental laws of a particular scientific discipline were first formulated.

In the development of any science, the first received paradigm is usually felt to account quite successfully for most of the observations and experiments easily accessible to that science’s practitioners. Further development, therefore, ordinarily calls for the construction of elaborate equipment, the development of an esoteric vocabulary and skills, and a refinement of concepts that increasingly lessens their resemblance to their usual common-sense prototypes. That professionalization leads, on the one hand, to an immense restriction of the scientist’s vision and to a considerable resistance to paradigm change. The science has become increasingly rigid. On the other hand, within those areas to which the paradigm directs the attention of the group, normal science leads to a detail of information and to a precision of the observation-theory match that could be achieved in no other way.

The extensive literature addressed to the definition or characterization of science is filled with inconsistent points of view and demonstrates that an adequate definition is not easy to attain. Part of the difficulty arises from the fact that the meaning of science is not fixed, but is dynamic. As science has evolved, so has its meaning. It takes on a new meaning and significance with successive ages.

In every branch of knowledge the progress is proportional to the amount of facts on which to build, and therefore to the facility of obtaining data.

All science must start with some assumptions as to the ultimate analysis of the facts with which it deals. These assumptions are justified partly by their adherence to the types of occurrence of which we are directly conscious, and partly by their success in representing the observed facts with a certain generality, devoid of ad hoc suppositions.