J. B. S. Haldane

"My practice as a scientist is atheistic. That is to say, when I set up an experiment I assume that no god, angel, or devil is going to interfere with its course; and this assumption has been justified by such success as I have achieved in my professional career. I should therefore be intellectually dishonest if I were not also atheistic in the affairs of the world."

"The commonest cause of gastritis – that is to say, an inflamed and irritable stomach – is worry and anxiety. It is particularly common among busmen and travelling salesmen. I had it for about fifteen years until I read Lenin and other writers, who showed me what was wrong with our society and how to cure it. Since then I have needed no magnesia. But these pains may also be due to gastric ulcer or even cancer. So it is better to consult a doctor, even though he will probably recommend magnesia. But the Daily Worker may effect a permanent cure."

"An inordinate fondness for beetles."

"I suppose the process of acceptance will pass through the usual four stages: (i) this is worthless nonsense; (ii) this is an interesting, but perverse, point of view; (iii) this is true, but quite unimportant; (iv) I always said so."

"An ounce of algebra is worth a ton of verbal argument."

"No, but I would to save two brothers or eight cousins."

"[F]our hundred years hence the power question in England may be solved somewhat as follows: The country will be covered with rows of metallic windmills working electric motors [generators] which in their turn supply current at a very high voltage to great electric mains. At suitable distances, there will be great power stations where during windy weather the surplus power will be used for the electrolytic decomposition of water into oxygen and hydrogen. ...In times of calm, the gasses will be recombined in explosion motors working dynamos which produce electrical energy once more, or more probably in oxidation cells."

"is weight for weight the most efficient known method of storing energy, as it gives about three times as much heat per pound as petrol. ...[I]t is very light, and bulk for bulk has only one third of the efficiency of petrol. This will not, however, detract from its use in aeroplanes, where weight is more important than bulk."

"These huge reservoirs of liquified gasses will enable wind energy to be stored, so that it can be expended for industry, transportation, heating and lighting, as desired. The initial costs will be very considerable, but the running expenses less than those of our present system. Among its more obvious advantages will be the fact that energy will be as cheap in one part of the country as another, so that industry will be greatly decentralized; and that no smoke or ash will be produced."

"There is no great invention, from fire to flying, which has not been hailed as an insult to some god."

"The conservative has little to fear from the man whose reason is the servant of his passions, but let him beware of him in whom reason has become the greatest and most terrible of passions. These are the wreckers of outworn empires."

"The conservative has but little to fear from the man whose reason is the servant of his passions, but let him beware of him in whom reason has become the greatest and most terrible of the passions. These are the wreckers of outworn empires and civilisations, doubters, disintegrators, deiciders."

"Science is as yet in its infancy, and we can foretell little of the future save that the thing that has not been is the thing that shall be; that no beliefs, no values, no institutions are safe. So far from being an isolated phenomenon the late war is only an example of the disruptive result that we may constantly expect from the progress of science. The future will be no primrose path. It will have its own problems. Some will be the secular problems of the past, giant flowers of evil blossoming at last to their own destruction. Others will be wholly new. Whether in the end man will survive his ascensions of power we cannot tell. But the problem is no new one. It is the old paradox of freedom re-enacted with mankind for actor and the earth for stage...But it is only hopeful if mankind can adjust its morality to its powers."

"The time has gone by when a Huxley could believe that while science might indeed remould traditional mythology, traditional morals were impregnable and sacrosanct to it. We must learn not to take traditional morals too seriously. And it is just because even the least dogmatic of religions tends to associate itself with some kind of unalterable moral tradition, that there can be no truce between science and religion. There does not seem to be any particular reason why a religion should not arise with an ethic as fluid as Hindu mythology, but it has not yet arisen. Christianity has probably the most flexible morals of any religion, because Jesus left no code of law behind him like Moses or Muhammad, and his moral precepts are so different from those of ordinary life that no society has ever made any serious attempt to carry them out, such as was possible in the case of Israel and Islam. But every Christian church has tried to impose a code of morals of some kind for which it has claimed divine sanction. As these codes have always been opposed to those of the gospels a loophole has been left for moral progress such as hardly exists in other religions. This is no doubt an argument for Christianity as against other religions, but not as against none at all, or as against a religion which will frankly admit that its mythology and morals are provisional. That is the only sort of religion that would satisfy the scientific mind, and it is very doubtful whether it could properly be called a religion at all."

"Now if we want poets to interpret physical science as Milton and Shelley did (Shelley and Keats were the last English poets who were at all up-to-date in their chemical knowledge), we must see that our possible poets are instructed, as their masters were, in science and economics."

"You can drop a mouse down a thousand-yard mine shaft; and, on arriving at the bottom, it gets a slight shock and walks away. A rat would probably be killed, though it can fall safely from the eleventh story of a building; a man is killed, a horse splashes."

"To the biologist the problem of socialism appears largely as a problem of size. The extreme socialists desire to run every nation as a single business concern. I do not suppose that Henry Ford would find much difficulty in running Andorra or Luxembourg on a socialistic basis. He has already more men on his pay-roll than their population. It is conceivable that a syndicate of Fords, if we could find them, would make Belgium Ltd. or Denmark Inc. pay their way. But while nationalization of certain industries is an obvious possibility in the largest of states, I find it no easier to picture a completely socialized British Empire or United States than an elephant turning somersaults or a hippopotamus jumping a hedge."

"It seems to me immensely unlikely that mind is a mere by-product of matter. For if my mental processes are determined wholly by the motions of atoms in my brain I have no reason to suppose that my beliefs are true. They may be sound chemically, but that does not make them sound logically. And hence I have no reason for supposing my brain to be composed of atoms."

"In scientific thought we adopt the simplest theory which will explain all the facts under consideration and enable us to predict new facts of the same kind. The catch in this criterion lies in the word "simplest." It is really an aesthetic canon such as we find implicit in our criticisms of poetry or painting. The layman finds such a law as {\mathrm{\partial }x \over \mathrm{\partial } t} = \Kappa { \, \mathrm{\partial}^2x \over \mathrm{\partial }y^2} much less simple than "it oozes," of which it is the mathematical statement. The physicist reverses this judgment, and his statement is certainly the more fruitful of the two, so far as prediction is concerned. It is, however, a statement about something very unfamiliar to the plain man, namely, the rate of change of a rate of change."

"Now, my own suspicion is that the universe is not only queerer than we suppose, but queerer than we can suppose.....I suspect that there are more things in heaven and earth than are dreamed of, or can be dreamed of, in any philosophy. That is the reason why I have no philosophy myself, and must be my excuse for dreaming."

"I have no doubt that in reality the future will be vastly more surprising than anything I can imagine."

"We must... carefully distinguish between two quite different doctrines which Darwin popularised, the doctrine of evolution, and that of natural selection. It is quite possible to hold the first and not the second. Similarly with regard to the doctrines of Darwin's great contemporary Marx, it is possible to adopt socialism but not historical materialism."

"I do not propose to argue the case for evolution, which I regard as being quite as well proven as most other historical facts, but to discuss its possible causes, which are certainly debatable."

"Darwin believed that the crossing of two types generally led to a blend, and that consequently bisexual reproduction tended to make a species uniform. He therefore had to postulate some cause constantly at work to keep up the inheritable variation within a species. He very naturally looked to the effects of differences of environment. ...It was shown that Darwin had been wrong in supposing that variations due to environment were inheritable. Selection merely picked out the best available line from a given population, and would not, as Darwin had believed, give rise to an unlimited amount of change."

"While the geneticists were disproving many of Darwin's ideas, the palaeontologists were determining the actual historical facts of evolution. ...they were able to verify the law of succession, first explicitly given by Darwin's colleague Wallace. "Every species has come into existence coincident, both in time and space, with a pre-existing closely allied species.""

"Evolution in... cases has clearly been a very slow and almost (if not quite) continuous process, exactly as Darwin had predicted. We must remember, however, that the organisms studied in this way are far from representative. They are in general the most successful members of animal associations living in very constant marine or lacustrine environments. We have not got similar data for land species... Nor do we possess them for the rarer forms. We shall see... that perhaps dominant species in a uniform environment are the least likely to undergo sudden change to a new type."

"Comparative parasitology supports the evolutionary hypothesis. If two animals have a common ancestor, their parasites are likely to be descended from those of the ancestor. This principle has been applied with considerable effect to the classification of frogs and other groups."

"The change from one stable equilibrium to the other may take place as the result of the isolation of a small unrepresentative group of the population, a temporary change in the environment which alters the relative viability of different types, or in several other ways..."

"Evolution must have involved the simultaneous change in many genes, which doubtless accounts for its slowness. Here matters would have been easier if heritable variations really formed a continuum, as Darwin apparently thought, i.e. if there were no limit to the possible smallness of a variation. But this is clearly not the case when we are considering meristic characters. ...the atomic nature of Mendelian inheritance suggests very strongly that even where variation is apparently continuous this appearance is deceptive."

"If the only available genes produce rather large changes, disadvantageous one at a time, then it seems to me probable that evolution will not occur in a random mating population. In a self-fertilised or highly inbred species it may do so if several mutations useful in conjunction, but separately harmful, occur simultaneously. Such an event is rare, but must happen reasonably often in wheat..."

"Where natural selection slackens, new forms may arise which would not survive under more rigid competition, and many ultimately hardy combinations will thus have a chance of arising. ...Thus the distinction between the principal mammalian orders seems to have arisen during an orgy of variation in the early Eocene which followed the doom of the great reptiles... Since that date mammalian evolution has been a slower affair, largely a progressive improvement of the types originally laid down in the Eocene. Another possible mode of making rapid evolutionary jumps is by hybridisation. ...hybridisation (where the hybrids are fertile) usually causes an epidemic of variation in the second generation which may include new and valuable types which could not have arisen within a species by slower evolution."

"If human evolution is to continue along the same lines as in the past, it will probably involve a still greater prolongation of childhood and retardation of maturity. Some of the characters distinguishing adult man will be lost. It was not an embryologist or palaeontologist who said, "Except ye . . . become as little children, ye shall not enter into the kingdom of heaven.""

"I have given my reasons for thinking that we can probably explain evolution in terms of the capacity for variation of individual organisms, and the selection exercised on them by their environment. ... The most obvious alternative to this view is to hold that evolution has throughout been guided by divine power. There are two objections to this hypothesis. Most lines of descent end in extinction, and commonly the end is reached by a number of different lines evolving in parallel. This does not suggest the work of an intelligent designer, still less of an all mighty one. But the moral objection is perhaps more serious. A very large number of originally free-living Crustacea, worms, and so on, have evolved into parasites. In doing so they have lost, to a greater or less extent, their legs, eyes, and brains, and have become in many cases the course of considerable and prolonged pain to other animals and to man. If we are going to take an ethical point of view at all (and we must do so when discussing theological questions), we are, I think, bound to place this loss of faculties coupled with increased infliction of suffering in the same class as moral breakdown in a human being, which can often be traced to genetical causes. To put the matter in a more concrete way, Blake expressed some doubt as to whether God had made the tiger. But the tiger is in many ways an admirable animal. We have now to ask whether God made the tapeworm. And it is questionable whether an affirmative answer fits in either with what we know about the process of evolution or what many of us believe about the moral perfection of God."

"Wright's theory certainly supports the view taken in this book that the evolution in large random-mating populations, which is recorded by palaeontology, is not representative of evolution in general, and perhaps gives a false impression of the events occurring in less numerous species. It is a striking fact that none of the extinct species, which, from the abundance of their fossil remains, are well known to us, appear to have been in our own ancestral line. Our ancestors were mostly rather rare creatures. " Blessed are the meek : for they shall inherit the earth.""

"Unaided common sense may indicate an equilibrium, but rarely, if ever, tells us whether it is stable. If much of the investigation here summarised has only proved the obvious, the obvious is worth proving when this can be done. And if the relative importance of selection and mutation is obvious, it has certainly not always been recognised as such."

"The universe is not only queerer than we imagine, but queerer than we can imagine."

"At Oxford, the young Haldane was frequently asked whether he was related to the "famous John Scott Haldane", his father, and he would answer "That depends on whether you consider identity to be a relationship.""

"J. B. S. Haldane counts fanaticism among the only four really important inventions made between 3000 B.C and 1400 A.D. It was a Judaic-Christian invention. And it is strange to think that in receiving this malady of the soul the world also received a miraculous instrument for raising societies and nations from the dead—an instrument of resurrection."

"Although Haldane accepted the earlier and incorrect paleontological interpretation of the fossil record of Gryphaea, in his overall belief that the pace of evolution was rapid and seemingly discontinuous, rather than slow and continuous, he anticipated, at least in part and by three decades, the model of punctuated equilibria, which was proposed by... Niles Eldredge and Stephen Jay Gould."