Science has been effective at furthering our understanding of nature because the scientific ethos is based on three key principles: (1) follow the evidence wherever it leads; (2) if one has a theory, one needs to be willing to try to prove it wrong as much as one tries to prove that it is right; (3) the ultimate arbiter of truth is experiment, not the comfort one derives from one's a priori beliefs, nor the beauty or elegance one ascribes to one's theoretical models.

No science of any kind can be divorced from ethical considerations... Science is a human learning process which arises in certain subcultures in human society and not in others, and a subculture as we seen is a group of people defined by acceptance of certain common values, that is, an ethic which permits extensive communication between them.

Ethics is the most vital and important of all sciences. It has both its theoretical and applied aspects. Its mission is nothing less than the establishment of harmony among the inhabitants of the earth and the transformation of world-wide contention into peace and happiness.

The core of science is not a mathematical modeling — it is intellectual honesty. It is a willingness to have our certainties about the world constrained by good evidence and good argument.

The core of science is not controlled experiment or mathetical modeling; it is intellectual honesty. It is time we acknowledge a basic feature of human discourse: when considering the truth of a proposition, one is either engaged in an honest appraisal of the evidence and logical arguments, or one isn't.

In science we must all submit not to what seems to us attractive from one point of view or another, but to what represents an agreement between theory and experiment.

We must start with scientific fundamentals, and that means with the data of experiments and not with assumed axioms predicated only upon the misleading nature of that which only superficially seems to be obvious. It is the consensus of great scientists that science is the attempt to set in order the facts of experience.

The enterprise of knowledge is consistent surely with science; it should be with religion, and it is essential for the welfare of the human species.

The attempt to discover and promulgate the truth is nevertheless an obligation upon all scientists, one that must be persevered in no matter what the rebuffs—for otherwise what is the point in being a scientist?

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.

The philosophy of science is as useful to scientists as ornithology is to birds.

When I had felt compelled by increasing knowledge of nature to revise some of my traditional articles of religious faith, I was delighted to find that these changes had not modified in any essential respects my system of ethics. As I expressed it in my presidential address before the American Association for the Advancement of Science in 1937:
"The ethics of science regards the search for truth as one of the highest duties of man; it regards noble human character as the finest product of evolution; it considers the service of all mankind as the universal good; it teaches that human nature and humane nurture may be improved, that reason may replace unreason, cooperation supplement competition, and the progress of the human race through future ages be promoted by intelligence and goodwill."

Science is about continuity of ideas, a web of connections.

A conviction akin to religious feeling of the rationality or intelligibility of the world lies behind all scientific work of a high order.