Ethics, 61 (1)
Oct. 1950, 27-37.
IT is widely assumed today that the pursuit of science represents a field of intellectual activities which does not require the acceptance of any doubtful beliefs. Science is taken to be, by its very nature, positive and demonstrable, differing in this respect not only from religious belief but also from any ethical conviction, such as a belief in justice or any other moral standard to which we are committed.
As early as John Locke a distinction of this kind was drawn in respect to religious truths. These, Locke says, are not capable of demonstration, “how well-grounded and great soever the assurance of faith may be wherewith it is received; but faith it is still and not knowledge; persuasion and not certainty.”  The two and a half centuries of scientific triumphs that have passed since Locke drew this distinction between faith and demonstrable knowledge have greatly added to the prestige of science as the embodiment of knowledge that is unambiguous and objective. A passionate affirmation of what some scientists believe science to be was given in recent years by the distinguished American psychologist, Clark L. Hull, in his Principles of Behavior. The essence of scientific objectivity lies, he says, in establishing rigorous mathematical relations between measured variables. Given the values of one set of variables, science predicts exactly the values of another set. A genuine scientific theory must operate like a calculating machine, which, once the keys representing the dividend and the divisor have been depressed, determines the result automatically. 
Such testimonies of scientists to the exactitude and objectivity of science carry conviction far and wide today. Indeed, I would hardly venture to oppose them here but for the recent occurrence of a massive event that is very difficult to reconcile with this conception of science. It has happened that “a great scientific nation has repudiated certain basic elements of scientific method and in so doing has repudiated the universal and supranational character of science.” The words are by Julian Huxley, writing on Soviet genetics in Nature of June 18, 1949, and I think that they give a correct description of the schism between the scientific opinions of the West and the views of scientists under communism. They show that certain substantial parts of science, which carry conviction and are accordingly recognized as science in one part of the world, fail to convince and are contemptuously rejected in another part. This seems to call seriously into question the claim that science is rigorous and impersonal and suggests that there are certain not indubitable beliefs involved in our acceptance of science - of our science - as valid.
With this in mind, let me proceed to point out the very substantial flaws which the rigorously positive conception of science contains and show that it requires to be supplemented by fiducial elements - which I shall call “scientific beliefs” - if we are to draw a true picture of science.
It is easy to demonstrate that the positivistic model of science - so emphatically indorsed, for example, by Clark L. Hull in the passage which I quoted before - as a set of empirically established mathematical relations between measured variables is incomplete, so incomplete as to be no more than a caricature of science. Suppose that the evidence on which a scientific proposition is to be based consists of a number of measurements made at various observed times, or else in coincidence with a series of observations made on some other measurable parameter. Let us, in other words, have pairs of two measured variables X and Y. Can we ever decide from a series of points of X plotted against Y whether there exists a functional relationship X = f(Y) and, if so, what it is? Clearly, we can do nothing of the kind. Any set of pairs of X and Y values is compatible with an infinite number of functional relations between which there is nothing to choose from the point of view of the underlying data. To choose any of the infinite possible functions and give it the distinction of a scientific proposition is so far without any justification. The measured data are insufficient for the construction of a definite function x = f(y) in exactly the same sense as two elements of a triangle are insufficient to determine a particular triangle.
It follows that, if scientific propositions were equivalent to mathematical functions of one exactly measurable variable depending on another exactly measurable variable, the chance of discovering any such proposition from the observation of the variable in question would be exactly zero. These propositions would be strictly underivable from the evidence to which they refer. Moreover, if they were, nevertheless, given in some inconceivable manner, these propositions would be strictly unverifiable. Successful prediction would not by itself achieve a finite measure of confirmation for the proposition in question. It would only add a number of observations, the predicted observations, to the previously given series of measurements and could not change the fact that any series of measurements is incapable of determining any particular function holding between the measured variables. 
Since some of you may be shocked by this conclusion (even though it merely restates what Hume said long ago), I shall illustrate it a little further. Suppose a player of roulette observes the number of reds and of blacks that turned up in a hundred consecutive throws. He may plot them in a graph and derive a function in the light of which he will make a prediction. He may try it out and win. He may try it again and win. And win a third time. Would that prove his generalization? No; in our view it would only prove that some roulette players are very lucky - i.e., we would consider the fulfillment of his predictions as mere coincidence.
A few years ago there appeared in Nature a table of figures proving with great accuracy that the time of gestation, measured in days, of a number of animals ranging from rabbits to cows is a multiple of the number π (see Table 1 HHC: nor reproduced). Yet an exact relationship of this kind makes no impression on the modern scientist, and no amount of further confirmatory evidence would convince him that there is any relation between the. period of gestation of animals and multiples of the number π.
It is, of course, not inconceivable that in one hundred years’ time people may think differently on this point. About one hundred years ago the great Helmholtz
declared: “Neither the testimony of all the Fellows of the Royal Society, nor even the evidence of my own senses could lead me to believe in the transmission of thoughts from one person to another, independently of the recognized channels of sensation.”  I think that scientists would no longer unanimously concur with the decision of Helmholtz to reject in advance all evidence of extra-sensory perception as fallacious, though very likely most of them would.
Not long ago listeners to the Third Programme in England were given a jolt by a broadcast discussion on astrology, in which an astrologist produced an array of carefully sifted evidence of astrological predictions that had come true. Possibly in another thousand years we shall be inclined to take such evidence seriously. Today we are not; and the fact remains that at all times there are a great many conceivable empirical relations that are rejected as absurd from the start and for which empirical evidence, therefore, is not accepted as valid, while evidence of a similar amplitude and apparent accuracy would be accepted as more than adequate to prove a relationship against which no such initial objection had been made.
This illustrates and substantiates the conclusion derived previously by the logical analysis of the positivistic model of science, namely, that the fulfillment of predictions in terms of observations is not in itself capable of validating a scientific statement. And we may add that even the converse of this is true. Our general conceptions of the nature of things cannot be strictly contradicted by experience, for they can always be expanded so as to cover any experience. This is often true even of specific scientific theories. We may quote as an example the Copernican theory of cycles and epicycles, which is capable of covering, to any required measure of approximation, any conceivable planetary motion. Or take Dalton’s law of simple chemical proportions or Hauy’s law of rational indices in crystallography. No observed chemical compositions of two compounds can flatly contradict Dalton’s law, for its
TABLE 1 HHC: not reproduced
prediction is not exactly determinate, and the same is true of the law of rational indices in crystallography.
This is not to say that a theory cannot sometimes be flatly contradicted by observation. But the current positivistic story that a scientist immediately drops a hypothesis the moment it conflicts with experience is a pure myth. No true scientist acts in this clumsy manner. Niels Bohr did not drop his theory of spectra, which was confirmed only by one single type of atom - that of hydrogen - and broke down at the very next step, when applied to helium. The periodic system of elements was not abandoned when two pairs of elements could be fitted into it only in the reverse sequence of their atomic weights. Chemistry held on firmly to the cyclic formula of benzene proposed by Kekule in 1859, even though it became clear, as the years passed by, that the two different di-substituted deriva-
tives which it postulated did not, in fact, exist. Scientists will often tolerate such contradictions to their theory, regarding them as anomalies which may be eliminated in the course of time by an amplification of the theory. Whether they should abandon a theory or not in any particular case can be determined by no fixed rule. The scientist’s decision depends on the strength of the beliefs in the light of which he interprets his observations, and we approve of this decision if we share these beliefs.
Those who are convinced that science can be based exclusively on data of experience have tried to avoid the weight of such critical analysis by reducing the claims of science to a more moderate level. They point out that scientific propositions do not make claim to certainty but claim only to be likely; that they make only provisional statements, which are always subject to revision.
These reservations are, however, beside the point. If anyone claims that, given two angles, he can construct the triangle, his claim is equally nonsensical whether he claims to give a true construction or merely a probable construction or the construction of a merely probable triangle. The selection of one element out of an infinite set of elements all of which satisfy the conditions set by the problem remains equally unjustifiable whatever positive quality we attach to our selection. Its value is exactly nought. In fact, scientists would object just as much to serial rules in games of chance or to astrological predictions or to relations between the time of gestation of animals and the number π, whether these are claimed with certainty, only with probability, or even merely provisionally. They would be regarded as no less nonsensical for that.
Such efforts to minimize the claims of science in order to make scientific discovery less puzzling remind one of the debate about the actual distance which the martyr St. Penis covered away from Montmartre, carrying his head in his arms. Mme du Deffand settled this neatly by exclaiming, “But surely, in such a situation ce n’est que le premier pas qui coute!” (“it is only the first step that counts”).
Other attempts to lessen the burden of responsibility on the scientists’ shoulders do not prove more successful. Science, it is urged, does not claim to discover the truth but only to give a description or summary of observational data. But why then object to astrology or to the description of periods of pregnancy in multiples of the number π? Surely for no other reason than that they are not held to be true or rational descriptions, which brings the problem back exactly to our starting point.
It has been suggested that scientists are giving the simplest description of their observations. But this is blatantly false. Scientists do not reject astrology, magic, the coincidence of pregnancy periods with multiples of the number π, or extra-sensory perception because these are not simple descriptions of the observed facts. And I would even say that human ingenuity could devise no more involved description than that given by the general theory of relativity, of the facts to which this theory refers. The adjective “simple” can be used as a distinctive mark of scientific statements only if it is tortured into meaning “rational” and finally made to coincide with “true,” which brings us back again to where we stood before.
The fact that serious and wise people with penetrating minds have so long subscribed to such rigmaroles about the nature of science can be understood only
as expressing a deep, underlying urge of our modern civilization. It is due to a fundamental reluctance to recognize our higher faculties, which our empiricist philosophy cannot account for. We dread to be caught believing - and, in fact, knowing - things which are not demonstrable by the measurement of observed variables. So we fabricate all kinds of pretenses and excuses and describe our most profound insights as merely “economic descriptions” and speak of our most assured convictions as mere “working hypotheses.” This serves us as a verbal screen behind which to hide our philosophically unaccountable power of discovering the truth about nature and our wholehearted commitment to the truths which we have so obscurely acquired.
The positivistic movement is, of course, only part of the general trend engendered by modern empiricism, which induces us to camouflage in utilitarian colors our transcendent faculties and obligations, in order that they may pass muster before a skeptical philosophy. Like clowns imitating puppets, we pretend to be pulled by strings, so as to conform with a mechanistic conception of man. It is part of this pattern that we dare not confess that we hold the scientific beliefs which we actually hold, for fear of the empiricist policeman behind us. We look carefully over our shoulder and pick our words appropriately, to avoid saying anything so metaphysical as that science inquires into the nature of things or that it seeks to explain them - for fear of offending the ruling assumptions about the strictly empirical origin of science.
Yet this is precisely the clue which we must pursue in order to replace the positivistic model by a more adequate reference to science. We must openly declare the beliefs which we hold about the nature of things, which guide our pursuit of science. We must admit that these beliefs are acquired by us uncritically in the course of our early education or subsequent apprenticeship to science and that no succeeding critical examination of these basic beliefs can ever eliminate all fiducial elements of our thinking. Let me turn to the exposition of this situation.
Our most general belief, which underlies all our scientific thinking, is the naturalistic view of the universe that is current among us today. When a scientist rejects in limine any empirical evidence for the reliability of predictions from horoscopes, for the potency of magic or the powers of witchcraft, he acts in the light of the naturalistic conception of things inculcated in us by our earliest upbringing. We do not take to this enlightened view of nature as a matter of course, without any pressure from outside. On the contrary, there seems to exist a strong natural bias toward a magical view of the world in which all events that affect us appear to embody an intention on the part of personal forces. As small children we encounter the objects of our surroundings indiscriminately as personal agencies. The I-Thou relationship which we establish with persons prevails also in our intercourse with impersonal objects. Only later do we class these objects in an I-It relationship and recognize the distinction between persons and things. All works of fiction and all but the driest chronicles of history embody important elements of the magical outlook. In an epic poem or in a novel nothing happens to a character that is not meaningful in the context of the story. Accidental death in a novel is never truly accidental, that is to say, truly meaningless, but is an event fitting
into the context of values to which the author bears witness. The magical outlook is similar to that of the child, in that it lacks the clear subject-object relation of modern man; and it resembles the world of fiction in the assumption that anything that happens to man is part of a meaningful story. Modern education breaks down our natural predilections which favor the magical outlook and inculcates in us certain conceptions which primitive people do not possess. Thus we acquire a clear subject-object relationship and the idea of natural causes, a corollary to which is the conception of accident. Lévy-Bruhi has shown that this supposition forms the logical basis of the naturalistic outlook, according to which events affecting human fate may be purely accidental, i.e., entirely meaningless.
We acquire our naturalistic system of explanations as we first acquire speech, uncritically absorbing the idiom of our elders. We do not learn our mother-tongue in preference to a hundred other living languages, as well as Esperanto, Ido, ancient Etruscan, and the language of the Principia mathematica, after examining the vocabularies and grammars of each and testing their relative appropriateness. We are born into a language, and we are also born into a set of beliefs about the nature of things. And, once brought up in our beliefs, we embrace them with sufficient conviction to participate in imposing them on the next generation. We wager our lives on these beliefs, and we share in building on these beliefs the life of the whole community which holds them. Indeed, this community is largely constituted by this joint commitment. It is dedicated to the pursuit of a technology and a science, of a system of jurisdiction and of political discussion, and of a way of life in general that is profoundly affected by the holding of these constitutive beliefs.
People brought up in a system of magic, witchcraft, and oracles are equally committed to their beliefs. Evidence which in our eyes would blatantly expose the worthlessness of their oracles does not in the least embarrass such people. This was made abundantly clear by Evans-Pritchard in his work on the Central African tribe of Azande. “Azande,” he says, “observe the action of the oracle as we observe it, but their observations are always subordinated to their beliefs and are incorporated into their beliefs and made to explain them and justify them. Let the reader consider any argument that would utterly demolish all Zande claims for the power of the oracle. If it were translated into Zande modes of thought it would support their entire structure of beliefs.  Their blindness (as we would regard it), far from being due to stupidity, is sustained by a remarkable ingenuity. “They reason excellently,” writes Evans-Pritchard, “in the idioms of their beliefs, but they cannot reason outside or against their beliefs because they have no other idiom in which to express their thoughts.” 
It is unquestionable that if you or I had been brought up among Azande, we would think as they do and be impervious to the evidence which now convinces us of the foolishness of their beliefs. This inevitably raises the stock argument used by religious doubters for centuries, which points out that beliefs accepted uncritically on the strength of a local authority will always testify to their own validity but that such testimony is worthless and that therefore such beliefs are unfounded. Yet we do not accept this argument in respect to the different beliefs which Azande and ourselves hold with regard to the nature
of things. I at any rate am prepared to congratulate myself on not having been brought up in a system of beliefs, such as those held by Azande, which I would otherwise falsely believe in. This is admittedly like saying that I am glad I dislike spinach, as otherwise I would eat it, though I hate it. When we pat ourselves on the back for being more enlightened than Azande, we rely on the same authority to which we blindly submitted in acquiring the supposed enlightenment. The witness which we bear to this authority is part of its own teaching. And this is quite proper. The regional diversity of beliefs and their social rootedness can shake our beliefs only if these are already losing ground for other reasons.
It is indeed logically impossible for the human mind to divest itself of all uncritically acquired foundations. For our minds cannot unfold at all except by embracing a definite idiom of beliefs, which will inevitably determine the scope of our entire subsequent fiducial development. As Evans-Pritchard observes, even the doubters among Azande express their dissent in alternative Zande beliefs. This is not to say that our beliefs are immutable. They are constantly remolded in the course of being applied to new objects. I shall illustrate in a moment how great pioneers, like Pythagoras or Galileo, opened up new vistas of scientific beliefs which guided subsequent periods of research. I myself believe that even our commonly accepted naturalistic I-It relation may need revision in its application to man, so as to avoid impairing our appreciation of man as a responsible moral being. But we must not fall into Zeno’s fallacy of assuming that something that is in flux or in motion is therefore not at some particular place at every moment. There are no limits set to the process of critical reflection, including, of course, our taking into account what people believe elsewhere and what we ourselves may think in the future. But, for all that, there is always a set of beliefs to which we are committed at any particular moment. And this commitment is, of necessity, largely determined by the first uncritical acceptance of our education in early life. In our own case, the case of modern man, we are committed in this manner to a naturalistic conception of the universe which is the major unrebuttable premise of all modern natural science.
Such disclosures of the fiducial foundations of science may be annoying to those brought up to regard science as universal and strictly objective, as an aggregate of x = f(y) functions vigorously derived from measured data. They may feel uneasy at being deprived of their ideal of science in the image of Clark L. Hull’s calculating machine, clicking out strictly impersonal responses. I should like to offer them a reply to their apprehensions, even though by so doing I may momentarily add to their vexation, by evoking here the shades of St. Paul. I would suggest that, instead of analyzing the powers of science as something operating outside us, we try to clarify the obligations incumbent on a scientist, since that is what we are concerned with and, indeed, that is all we have to do. The simplest expression that I know of the scientist’s obligation can be stated in terms of the Christian paradox, that man is called upon to try the impossible but is not expected to achieve it. As scientists we must seek a truth which is unambiguous and universal, even though at the same time we must recognize that this is impossible and, indeed, strictly speaking, meaningless. In science, just as in the
jury-box or in the voting-booth or in the recruiting office, you must commit yourself on grounds which, on reflection, must necessarily appear deficient. In science, as elsewhere, we must choose, within the limits of time and other given circumstances, whether to affirm or to refrain from affirming and what to say and how to say it. Whatever our decision, it will fulfill our whole obligation if we have previously exhausted, within the limits imposed by the situation, the requirements of our ideal as interpreted by our conscience. All that can be required of us is that we should seek the universal in the light of such guidance as we possess. It is not required of us that we should decide our problems on the supposition that we were born in no particular place, in no particular time, and endowed with no personal judgment of our own. The fellow in the old joke who tells you, when you ask your way, that “he would not start from there” is talking logical nonsense. Our duty is always here and now; and mercifully that is all that is demanded of us. If we had been born among Azande, we would have Zande problems; as it is, we have our own, which include, as they do not include for Azande, the pursuit of science.
But perhaps I had better resume the exposition of the fiducial foundations of science so as to have an ampler range of reference on which to base my analysis. Consider our rejection of evidence purporting to show that the period of gestation of animals measured in terrestrial days is a multiple of the number π. This rejection does not follow from our naturalistic outlook and, indeed, expresses a comparatively recent belief of science. I should say that a scientist like Kepler would by no means have regarded as absurd the relationship suggested here.
He had himself derived the existence of the seven planets and the relative sizes of their orbits by speculations of a similar kind. Take the five regular solids, or “perfect solids,” as they used to be called - the tetrahedron, the cube, the octahedron, etc. - constructing a sample of each with the same length of edge. They form a series of increasing size, and you can imagine each polyhedron contained in the next. Then draw the inscribed and enveloping spheres, and you obtain, according to Kepler’s theory, the orbits of the six planets recognized in Kepler’s time. Today this suggestion appears absurd to scientists, though there are many people regarded by scientists as cranks who adhere to the older scientific belief, going back to Pythagoras, that nature is governed by number rules and standards of geometrical perfection. We should bear in mind that the revival of science by Copernicus was based on Pythagorean suppositions. To Copernicus, as to Pythagoras twenty-one hundred years before him, the problem of astronomy was defined as the explanation of the heavenly events on the assumption of circular and uniform motion.
It was only with Galileo and Gassendi, at the opening of the seventeenth century, that mathematical relationships were reduced to mere expressions of mechanical laws, while the presuppositions of science concerning the nature of things underwent a transformation on the lines of the ancient Democritean atomistics. In this view the real nature of things does not consist in numbers but is constituted by matter in motion. This conception of the universe as an aggregate of material particles which in themselves are colorless and tasteless and neither hot nor cold - just as needles are in themselves neither pricking nor
stitching - set out a new program for science which still largely dominates the popular imagination today. The ideal pursued by this program was defined in the eighteenth century by Laplace in his Mechanique céleste; “An intelligence knowing at a given instant of time all forces acting in nature as well as the momentary positions of all things… would be able to comprehend the motions of the largest bodies of the universe and those of the lightest atoms in one single formula, provided his intellect were powerful enough to subject all data to analysis; to him nothing would be uncertain, both past and future would be present to his eyes.”
What Laplace says here by no means sounds so absurd today as do Pythagorean teachings; yet, actually, Laplace’s belief is no longer accepted in science. The assumption that only extension, mass, and motion are primary properties of matter became an obstacle to scientific progress as far back as Faraday’s investigation of electricity and magnetism. The discovery of the electron was long delayed on account of the reluctance to admit that electrical properties should be regarded as ultimate qualities, not reducible - like heat, noise, smell, etc. - to mass in motion. The assumptions of Galileo and Laplace led also to a mass of futile speculations about the mechanical properties of the electromagnetic ether. And, finally, it turned out that the conception of Newtonian space as a framework at absolute rest, which is implicit in Laplace’s vision, is absurd and must be discarded.
The recklessness of Laplace’s teaching is today fully exposed to the critical view, yet its convincing power is still alive. A contemplation of this skin which we have only just shed may help us to realize the nature of the commitment in which we are involved today in accepting science as valid. It reveals the two aspects of our actual scientific beliefs. Every belief is both a free gift and the payment of a tribute exacted from us. It is given on the personal responsibility of the believer, yet in the clear assumption that he cannot do otherwise. The two poles of a fiducial commitment, the personal and the universal, thus become apparent, and we can see that they are logically complementary and inseparable.
Hence we can now discern the fundamental fallacy of the positivist model of science. It tries to construct a machine which will produce universally valid results. But universal validity is a conception which does not apply outside the commitment situation. Any reference to it is merely a manner of expressing our submission to an ultimate obligation and can appear only as part of a fiducial declaration. The attempt to construct something universally valid, prior to any belief, is logically nonsensical.
Science can never be more than an affirmation of certain things we believe in. These beliefs must be adopted responsibly, with due consideration of the evidence and with a view to universal validity. But eventually they are ultimate commitments, issued under the seal of our personal judgment. At some point we shall find ourselves with no other answer to queries than to say “because I believe so.” That is what no set of rules, or any model of science based on a system of rules, can do; it cannot say “because I believe so.” Only a person can believe something, and only I myself can hold my own beliefs. For the holding of these I must bear the ultimate responsibility; it is futile, and I think also ignoble, to hunt for systems and machines which will take that burden from
me. And we, as a community, must also face the fact that there is no system of necessary rules which will relieve us from the responsibility of holding the constitutive beliefs of our group or of teaching them to the next generation and defending their continued profession against those who would suppress them.
We can now more readily imagine that other people do not share these beliefs and are prepared to commit themselves to a somewhat different fiducial system. For example, J. B. S. Haldane wrote recently in connection with the Soviet genetics controversy that, if genes were unchangeable, he, as a Marxist, could not believe in them.  Thus Hal-dane’s anterior acceptance of Marxism determines to some extent his scientific beliefs. There is little doubt that Lysenko, Prezent, and a great number of their followers passionately believe that the Mendelian laws of inheritance are false, because in their view they contradict dialectical materialism and what they call “the revolutionary principle of changing nature for the benefit of the people.” 
There is also among Soviet thinkers a smoldering hostility to modern physics, which seriously flared up at the beginning of 1949 but has so far not led to a showdown.  It demands a return to the materialistic beliefs of Galileo-Gassendi-Laplace which were abandoned in the formulation of relativity and quantum mechanics. This materialistic conception, which has dominated men’s minds for three centuries and was held to be self-evident by critical philosophers of the caliber of Kant, is, of course, still strongly rooted in popular beliefs. Soviet philosophers may well find grounds for adopting it once more, even if this causes difficulties in modern science. We may recall that two great German physicists, both Nobel Laureates, Philip Lanard and Johannes Stark, adopted the same position less than fifteen years ago.
I think we should admit, therefore, that there is a genuine divergence of belief as to the nature of things between an important group of Communists both inside and outside Russia and almost all the non-Communist scientists in the West. Naturally, the Communists in question are trying to gain general acceptance for their fundamental premises by incorporating them in the curriculums of schools and universities. They try to displace everywhere scientists who in their view teach nonsense and pursue absurd lines of research by others who share their own fundamental beliefs.
We know that the process is speeded up by hateful forms of terror. But it would be equally destructive to the freedom of science if all the relevant decisions had been taken by democratic methods.
Apart from our detestation of their brutality, our objections to the intervention of the Soviet authorities in scientific life are all rooted in our disbelief of the new premises of science which they accept. There is hardly anything that Lysenko has done which would not be pardonable if it had been done to suppress some form of quackery that had become rampant in scientific institutions, so as to make way, instead, for the true methods of science. Ultimately, therefore, our protests must rest on the affirmation that our own scientific beliefs are true. There is no way of divesting ourselves of the responsibility for holding these beliefs and for committing ourselves to their dissemination and defense.
UNIVERSITY OF MANCHESTER
1. “A Third Letter for Toleration,” Works of Jonn Locke (10th ed.; London, 1801), VI, 144.
2. Clark L. Hull, Principles of Behavior (New York, 1943), p. 24.
3. Cf. my Science, Faith and Society (London: Oxford University Press, 1946), pp. 7 and 8.
4. Quoted by Jan Ehrenwald, Telepathy and Medical Psychology (1947), pp. 23-24.
5. E. E. Evans-Pritchard, Witchcraft, Oracles, and Magic among the Azande (Oxford, 1937).
6. Ibid., p. 338.
7. Modern Quarterly, Vol. IV, No. 3 (1949).
8. Proceedings of the Presidium of the U.S.S.R. Academy of Science, Aug. 26, 1948, quoted by J. Huxley, in Heredity East and West (New York: Henry Schuman, 1949), p. 39.
9. Eric Ashby, “The Pattern of Soviet Science,” Listener, XLIII, No. 1105 (March 30, 1950), 549-50