That of which tragedy died, the Socratism of morality, the dialectics, frugality, and cheerfulness of the theoretical man – might not this very Socratism be a sign of decline, of weariness, of infection, of an anarchical dissolution of the instincts? And the “Greek cheerfulness” of the later Greeks – merely the afterglow of the sunset? The Epicureans’ resolve against pessimism – a mere precaution of the afflicted? And science itself, our science – what is the significance of all science, viewed as a symptom of life? For what – worse yet, toward what – all science? Is the resolve to be so scientific about everything perhaps a fear of, an escape from, pessimism? A subtle last resort against – truth? Morally speaking, a sort of cowardice and falseness? Amorally speaking, a ruse?

It is still a metaphysical faith upon which our faith in science rests – even we seekers after knowledge today, we godless anti-metaphysicians still take our fire from the flame that was lit by a faith thousands of years old, that Christian faith which was also the faith of Plato, that God is the truth, that truth is divine. – But what if this should become more and more incredible, if nothing should prove to be divine anymore unless it were error, blindness, the lie – if God himself were to prove to be our most enduring lie?

No! Don’t come to me with science when I ask for the natural antagonist of the ascetic ideal, when I demand: “where is the opposing will expressing the opposing ideal?” Science is not nearly self-reliant enough to be that; it first requires in every respect an ideal of value, a value-creating power, in the service of which it could believe in itself – it never creates values. Its relation to the ascetic ideal is by no means essentially antagonistic; it might even be said to represent the driving force in the latter’s inner development. It opposes and fights, on closer inspection, not the ideal itself but only its exteriors, its guise and masquerade, its temporary dogmatic hardening and stiffening, and by denying what is exoteric in this ideal, it liberates what life is in it. This pair, science and the ascetic ideal, both rest on the same foundation – I have already indicated it: on the same overestimation of truth (more exactly: on the same belief that truth is inestimable and cannot be criticized). Therefore they are necessarily allies, so that if they are to be fought they can only be fought and called in question together. A depreciation of the ascetic ideal unavoidably involves a depreciation of science: one must keep one’s eyes and ears open to this fact.

Art, in which precisely the lie is sanctified and the will to deception has a good conscience, is much more fundamentally opposed to the ascetic ideal than is science: this was instinctively sensed by Plato, the greatest enemy of art Europe has yet produced. Plato versus Homer: that is the complete, the genuine antagonism – there the sincerest advocate of the “beyond”, the great slanderer of life; here the instinctive deifier, the golden nature. To place himself in the service of the ascetic ideal is therefore the most distinctive corruption of an artist that is at all possible.

With all these conceptions the steady and laborious process of science, which will one day celebrate its greatest triumph with a history of the genesis of thought, will in the end decisively have done; for the outcome of this history may well be the conclusion: That which we now call the world is the outcome of a host of errors and fantasies which have gradually arisen and grown entwined with one another in the course of the overall evolution of the organic being, and are now inherited by us as the accumulated treasure of the entire past – as treasure, for the value of our humanity depends upon it. Rigorous science is capable of detaching us from this ideational world only to a limited extent – and more is certainly not to be desired – as it is incapable of making any essential inroad into the power of habits of feeling acquired in primeval times: but it can, gradually and step by step, illuminate the history of the genesis of this world as idea – and, for brief periods at any rate, lift us up out of the entire proceeding. Perhaps we shall then realize that the ding an sich [thing in itself] is worthy of Homeric laughter: that it appeared to be so much, indeed everything, and is actually empty, that is to say empty of significance.

A ‘scientific’ interpretation of the world … might … be one of the most stupid of all possible interpretations of the world, meaning that it would be one of the poorest in meaning. This thought is intended for the ears and consciences of our mechanists who nowadays like to pass as philosophers and insist that mechanics is the doctrine of the first and last laws on which all existence must be based as on a ground floor. But an essentially mechanical world would be an essentially meaningless world. Assuming that one estimated the value of a piece of music according to how much of it can be counted, calculated, and expressed in formulas: how absurd would such a ‘scientific’ estimation of music be! Nothing, really nothing of what is ‘music’ in it!

– Friedrich Nietzsche

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 the first half 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 (1 with twenty-four zeros after it) 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. One of the major endeavors in physics today, and the major theme of this book, is the search for a new theory that will incorporate them both – a quantum theory of gravity. We do not yet have such a theory, and we may still be a long way from having one, but we do already know many of the properties that it must have. And we shall see, in later chapters, that we already know a fair amount about the predictions a quantum theory of gravity must make.

Now, if you believe that the universe is not arbitrary, but is governed by definite laws, you ultimately have to combine the partial theories into a complete unified theory that will describe everything in the universe. But there is a fundamental paradox in the search for such a complete unified theory. The ideas about scientific theories outlined above assume we are rational beings who are free to observe the universe as we want and to draw logical deductions from what we see. In such a scheme it is reasonable to suppose that we might progress ever closer toward the laws that govern our universe. Yet if there really is a complete unified theory, it would also presumably determine our actions. And so the theory itself would determine the outcome of our search for it! And why should it determine that we come to the right conclusions from the evidence? Might it not equally well determine that we draw the wrong conclusion? Or no conclusion at all?

The only answer that I can give to this problem is based on Darwin’s principle of natural selection. The idea is that in any population of self-reproducing organisms, there will be variations in the genetic material and upbringing that different individuals have. These differences will mean that some individuals are better able than others to draw the right conclusions about the world around them and to act accordingly. These individuals will be more likely to survive and reproduce and so their pattern of behavior and thought will come to dominate. It has certainly been true in the past that what we call intelligence and scientific discovery has conveyed a survival advantage. It is not so clear that this is still the case: our scientific discoveries may well destroy us all, and even if they don’t, a complete unified theory may not make much difference to our chances of survival. However, provided the universe has evolved in a regular way, we might expect that the reasoning abilities that natural selection has given us would be valid also in our search for a complete unified theory, and so would not lead us to the wrong conclusions.

Because the partial theories that we already have are sufficient to make accurate predictions in all but the most extreme situations, the search for the ultimate theory of the universe seems difficult to justify on practical grounds. (It is worth noting, though, that similar arguments could have been used against both relativity and quantum mechanics, and these theories have given us both nuclear energy and the microelectronics revolution!) The discovery of a complete unified theory, therefore, may not aid the survival of our species. It may not even affect our life-style. But ever since the dawn of civilization, people have not been content to see events as unconnected and inexplicable. They have craved an understanding of the underlying order in the world. Today we still yearn to know why we are here and where we came from. Humanity’s deepest desire for knowledge is justification enough for our continuing quest. And our goal is nothing less than a complete description of the universe we live in.

– Stephen Hawking

Imagination is more important than knowledge. For knowledge is limited, whereas imagination embraces the entire world, stimulating progress, giving birth to evolution.

It is not so very important for a person to learn facts. … He can learn them from books. The value of an education in a liberal arts college is not the learning of many facts, but the training of the mind to think something that cannot be learned from textbooks.

It has become appallingly obvious that our technology has exceeded our humanity.

It is not enough that you should understand about applied science in order that your work may increase man’s blessings. Concern for the man himself and his fate must always form the chief interest of all technical endeavors; concern for the great unsolved problems of the organization of labor and the distribution of goods in order that the creations of our mind shall be a blessing and not a curse to mankind. Never forget this in the midst of your diagrams and equations.

All religions, arts and sciences are branches of the same tree. All these aspirations are directed toward ennobling man’s life, lifting it from the sphere of mere physical existence and leading the individual towards freedom.

The important thing is not to stop questioning. Curiosity has its own reason for existing. One cannot help but be in awe when he contemplates the mysteries of eternity, of life, of the marvelous structure of reality. It is enough if one tries merely to comprehend a little of this mystery every day.

– Albert Einstein

Two things fill the mind with ever new and increasing admiration and awe, the more often and steadily we reflect upon them: the starry heavens above me and the moral law within me. I do not seek or conjecture either of them as if they were veiled obscurities or extravagances beyond the horizon of my vision; I see them before me and connect them immediately with the consciousness of my existence.

– Immanuel Kant

We feel that even if all possible scientific questions be answered, the problems of life have still not been touched at all.

– Ludwig Wittgenstein