A principle of induction would be a statement with the help of which we could put inductive inferences into a logically acceptable form. In the eyes of the upholders of inductive logic, a principle of induction is of supreme importance for scientific method: “... this principle”, says Reichenbach, “determines the truth of scientific theories. To eliminate it from science would mean nothing less than to deprive science of the power to decide the truth or falsity of its theories. Without it, clearly, science would no longer have the right to distinguish its theories from the fanciful and arbitrary creations of the poet’s mind.” Now this principle of induction cannot be a purely logical truth like a tautology or an analytic statement. Indeed, if there were such a thing as a purely logical principle of induction, there would be no problem of induction; for in this case, all inductive inferences would have to be regarded as purely logical or tautological transformations, just like inferences in inductive logic. Thus the principle of induction must be a synthetic statement; that is, a statement whose negation is not self-contradictory but logically possible. So the question arises why such a principle should be accepted at all, and how we can justify its acceptance on rational grounds.

As a progressive discipline [biochemistry] belongs to the present century. From the experimental physiologists of the last century it obtained a charter, and, from a few pioneers of its own, a promise of success; but for the furtherance of its essential aim that century left it but a small inheritance of facts and methods. By its essential or ultimate aim I myself mean an adequate and acceptable description of molecular dynamics in living cells and tissues.

Engineering is the art of directing the great sources of power in nature for the use and the convenience of people. In its modern form engineering involves people, money, materials, machines, and energy. It is differentiated from science because it is primarily concerned with how to direct to useful and economical ends the natural phenomena which scientists discover and formulate into acceptable theories. Engineering therefore requires above all the creative imagination to innovate useful applications of natural phenomena. It seeks newer, cheaper, better means of using natural sources of energy and materials.

How fortunate for civilization, that Beethoven, Michelangelo, Galileo and Faraday were not required by law to attend schools where their total personalities would have been operated upon to make them learn acceptable ways of participating as members of “the group.”

Modern music, headstrong, wayward, tragically confused as to what to say and how to say it, has mounted its horse, as the joke goes, and ridden off in all directions. If we require of an art that it be unified as a whole and expressed in a universal language known to all, if it must be a consistent symbolization of the era, then modern music is a disastrous failure. It has many voices, many symbolizations. It it known to one, unknown to another. But if an art may be as variable and polyvocal as the different individuals and emotional regions from which it comes in this heterogeneous modern world, then the diversity and contradiction of modern music may be acceptable.

On a perfect planet such as might be acceptable to a physicist, one might predict that from its origin the diversity of life would grow exponentially until the carrying capacity, however defined, was reached. The fossil record on Earth, however, tells a very different story.

Perhaps our and Gaia’s greatest error was the conscious abuse of fire. Cooking meat over a wood fire may have been acceptable, but the deliberate destruction of whole ecosystems by fire merely to drive out the animals within was surely our first great sin against the living Earth. It has haunted us ever since and combustion could now be our auto da fé, and the cause of our extinction.

Perhaps the earliest memories I have are of being a stubborn, determined child. Through the years my mother has told me that it was fortunate that I chose to do acceptable things, for if I had chosen otherwise no one could have deflected me from my path. ... The Chairman of the Physics Department, looking at this record, could only say 'That A- confirms that women do not do well at laboratory work'. But I was no longer a stubborn, determined child, but rather a stubborn, determined graduate student. The hard work and subtle discrimination were of no moment.

Science says: “We must live,” and seeks the means of prolonging, increasing, facilitating and amplifying life, of making it tolerable and acceptable, wisdom says: “We must die,” and seeks how to make us die well.

The present lack of a definitely acceptable account of the origin of life should certainly not be taken as a stumbling block for the whole Darwinian world view.

The specific goals we set for ourselves are almost always subsidiary to our long range intentions. A good parent, a good neighbour, a good citizen, is not good because his specific goals are acceptable, but because his successive goals are ordered to a dependable and socially desirable set of values. (1947)

To be acceptable as scientific knowledge a truth must be a deduction from other truths.

To us … the only acceptable point of view appears to be the one that recognizes both sides of reality—the quantitative and the qualitative, the physical and the psychical—as compatible with each other, and can embrace them simultaneously … It would be most satisfactory of all if physis and psyche (i.e., matter and mind) could be seen as complementary aspects of the same reality.

What makes the theory of relativity so acceptable to physicists in spite of its going against the principle of simplicity is its great mathematical beauty. This is a quality which cannot be defined, any more than beauty in art can be defined, but which people who study mathematics usually have no difficulty in appreciating. … The restricted theory changed our ideas of space and time in a way that may be summarised by stating that the group of transformations to which the space-time continuum is subject must be changed from the Galilean group to the Lorentz group.