Theories

Man is born for action; he ought to do something. Work, at each step, awakens a sleeping force and roots our error. Who does nothing, knows nothing. Rise! to work! If thy knowledge is real, employ it; wrestle with nature; test the strength of thy theories; see if they will support the trial; act!

I don’t see any reason why we should have less confidence in this kind of perception, I.e., in mathematical intuition, than in sense perception, which induces us to build up physical theories and to expect that future sense perceptions will agree with them and, moreover, to believe that a question not decidable now has meaning and may be decided in the future.

Education is not to teach men facts, theories or laws, not to reform or amuse them or make them expert technicians. It is to unsettle their minds, widen their horizons, inflame their intellect, teach them to think straight, if possible, but to think nevertheless.

All theories, all values, all reforms, all revolutions, all change, and all actions are built on the shifting sands of custom and opinion, and the winds of doubt and new circumstances and considerations are always blowing, always rising.

In spite of the fact that religion looks backward to revealed truth while science looks forward to new vistas and discoveries, both activities produce a sense of awe and a curious mixture of humility and arrogance in practitioners. All great scientists are inspired by the subtlety and beauty of the natural world that they are seeking to understand. Each new subatomic particle, every unexpected object, produces delight and wonderment. In constructing their theories, physicists are frequently guided by arcane concepts of elegance in the belief that the universe is intrinsically beautiful.

Today scientists describe the universe in terms of two basic partial theories – the general theory of relativity and quantum mechanics. They are the great intellectual achievements of this century. The general theory of relativity describes the force of gravity and the large-scale structure of the universe (that is the structure on scales from only a few miles to as large as a million million million million miles – the size of the observable universe). Quantum mechanics, on the other hand, deals with phenomena on extremely small scales, such as a millionth of a millionth of an inch. Unfortunately, however, these two theories are known to be inconsistent with each other – they cannot both be correct.

What the world needs is a sense of ultimate embarrassment. Modern man has the power and the wealth to overcome poverty and disease, but he has no wisdom to overcome suspicion. We are guilty of misunderstanding the meaning of existence; we are guilty of distorting our goals and misrepresenting our souls. We are better than our assertions, more intricate, more profound than our theories maintain.

Learn your theories but put them aside when you confront the mystery of the living soul.

Learning to learn is to know how to navigate in a forest of facts, ideas and theories, a proliferation of constantly changing items of knowledge. Learning to learn is to know what to ignore but at the same time not rejecting innovation and research.

Precisely what we need are good theories to focus our attention, a good set of ideals to guide our action, and good visions of the future to mobilize our energies.

Scientific evidence is accretionary, built from blocks of evidence joined artfully by the blueprints and mortar of theory. Only very rarely, as in the theories of natural selection and relativity, does an idea change our conception of the world in one quantal leap.

Scientists look for four qualities in theory generally… parsimony: the fewer the units and process used to account for the phenomenon, the better… second, generality: the greater the range of phenomena covered by the model, the more likely it is to be true… Consilence: units and process of a discipline that conform with solidly verified knowledge in other disciplines have proven consistently superior in theory and practice to units and processes that do not conform… Predictiveness: those theories endure that are precise in the predictions they make across phenomena and whose predictions are easiest to test by observation and experiment.

I remember that one time Carl [Sagan] was giving a talk, and he spelled out, in a kind of withering succession, these great theories of demotion that science has dealt us, all of the ways in which science is telling us we are not who we would like to believe we are. At the end of it, a young man came up to him and he said: "What do you give us in return? Now that you've taken everything from us? What meaning is left, if everything that I've been taught since I was a child turns out to be untrue?" Carl looked at him and said, "Do something meaningful."

I have never seen the slightest scientific proof of the religious theories of heaven and hell, of future life for individuals, or of a personal God.

Today scientists describe the universe in terms of two basic partial theories - the general theory of relativity and quantum mechanics... The general theory of relativity describes the force of gravity and the large-scale structure of the universe, that is, the structure on scales from only a few miles to as large as a million million million million (1 with twenty-four zeros after it) miles, the size of the observable universe. Quantum mechanics, on the other hands, deals with phenomena on extremely small scales, such as a millionth of a millionth of an inch. Unfortunately, however, these two theories are known to be inconsistent with each other - they cannot both be correct.

I have taken pains to show that financial markets left to their own devices don't tend towards an equilibrium that assures an optimum allocation of resources. The theories of efficient markets and rational expectations don't stand up to critical examination.

Art is never didactic, does not take kindly to facts, is helpless to grapple with theories, and is killed outright by a sermon.

Art is never didactic, does not take kindly to facts, is helpless to grapple with theories, and is killed outright by a sermon.

Art is never didactic, does not take kindly to facts, is helpless to grapple with theories, and is killed outright by a sermon.

Lack of experience diminishes our power of taking a comprehensive view of the admitted facts. Hence those who dwell in intimate association with nature and its phenomena grow more and more able to formulate, as the foundation of their theories, principles such as to admit of a wide and coherent development: while those whom devotion to abstract discussions has rendered unobservant of the facts are too ready to dogmatize on the basis of a few observations.