The Church And The Experimental Method
( Originally Published 1911 )
There is a very generally accepted false impression with regard to the attitude maintained by the Church during the Middle Ages, especially toward what is known as the experimental method in the gaining of knowledge, or as we would now say, in the study of science. It is commonly supposed that at least before the sixteenth century, though of course in modern times it has had to change its attitude to accord with the advances of modern science, the Church was decidedly opposed to the experimental method, and that the great ecclesiastical scholars of the wonderful period of the rise of the universities were all absolute in their confidence in authority and their dependence on the deductive method as the only means of arriving at truth. This widespread false impression owes its existence and persistence to many causes.
It is supposed by many of those outside the Church that there is a distinct incompatibility between the state of mind which accepts things on faith and that other intellectual attitude which leads man to doubt about his knowledge and consequently to inquire. This doubting frame of mind, which is readily recognized to be absolutely necessary for the proper pursuit of experimental science, is supposed quite to preclude the idea of the peaceful settlement of the doubts that assail men's minds as to the significance of life, of the relation of man to man and to his Creator, and the hereafter, which comes with the acceptance of what revelation has to say on these subjects. Somehow, it is assumed by many people that there is something mutually and essentially repellent in these two forms of assent. If a man is ready to accept certain propositions on authority and without being able to understand them, and still more, if he accept them, realizing that he cannot understand them, it is considered to be impossible for him to be able to assume such a mental attitude towards science as would make him an original investigator.
It is almost needless to say to anyone who knows anything about the history of modern science even nineteenth century science, that there is absolutely no foundation for this prejudice. Most of our greatest investigators even in nineteenth century science have been faithful believers not only in the ordinary religious truths, in a Providence, in a hereafter, and in this life as a preparation for another, but also in the great mysteries of revelation. I have shown this amply even with regard to what is usually considered so unorthodox a science as medicine, in my volume on the Makers of Modern Medicine. Most of the men who did the great original work in last century medicine were Catholics. The same thing is true for electricity, for example. All the men after whom modes and units of electricity are named Galvani, Volta, Coulomb, Ampère, Ohm were not only members of the Church, but what would be even called devout Catholics.
A second and almost as important a reason for the superstition for it is a supposed truth accepted without good reasons therefor that somehow the Church was opposed to the inductive or experimental method, is the persistent belief which, in spite of frequent contradictons, remains in the minds of so many scientists, that the inductive or experimental method was introduced to the world by Francis Bacon, the English philosopher, at the beginning of the seventeenth century. Bacon himself was a Protestant ; he did not do his writing until the reformation so-called had been at work in Europe for nearly a century, and somehow it is supposed that these facts are linked together as causes and effects. The reason why such a formulation of the inductive method had not come before was because this was forbidden ground ! Nothing could be less true than that Lord Bacon had any serious influence in bringing about the introduction of the inductive method into science. At most he was a chronicler of tendencies that he saw in the science of his day. It is true that his writings served to give a certain popular vogue to the inductive method, or rather a certain exaggerated notion of the import of experiment to those who were not themselves scientists. Bacon was a popular writer on science, not an original thinker or worker in the experimental sciences. Popularizers in science, alas ! have from Amerigo Vespucci down reaped the rewards due to the real discoverers.
Induction in the genuine significance of the word had been recognized in the world long before Bacon's time and been used to much better effect than he was able to apply it. Personally, I have always felt that he has almost less right to all the praise that has been bestowed on him for what he is supposed to have done for science, than he has for any addition to his reputation because of the attribution to him by so many fanatics of the authorship of Shakespeare's plays. It is rather difficult to understand how his reputation ever came about. Lord Macaulay is much more responsible for it than is usually thought ; his brilliancy often overreached itself or went far beyond truth his favorite geese were nearly always swans, in his eyes.
De Maistre, in his review of Bacon's Novum Organum, points out that this work is replete with prejudices ; that Bacon makes glaring blunders in astronomy, in logic, in metaphysics, in physics, in natural history, and fills the pages of his work with childish observations, trifling experiments, and ridiculous explanations. Our own Professor Draper, in his Intellectual Development of Europe, has been even more severe, and has especially pointed out that Bacon never received the Copernican System, but " with the audacity of ignorance he presumed to criticise what he did not understand, and with a superb conceit disparaged the great Copernicus. The more closely we examine the writings of Lord Bacon," he says farther on, "the more unworthy does he seem to have been of the great reputation which has been awarded to him. . . The popular delusion, to which he owes so much, originated at a time when the history of science was unknown. This boasted founder of a new philosophy could not comprehend and would not accept the greatest of all scientific discoveries when it was plainly set before his eyes."
As a student of the history of medicine, it has always been especially irritating to me to hear Francis Bacon's name heralded as the Father of Experimental Science. Literally hundreds of physicians had applied the experimental method in its perfect form to many problems in medicine and surgery during at least three centuries or more before Bacon's time. They did not need to have the principles of it set forth for them by this publicist, who knew how to write about scientific method, but did not know how to apply it, so far as we know anything about him ; and who was utterly unable to see the great discoveries that had been made by the experimental method in the century before his time, and refused to accept such great advances in science as were made by Copernicus and others. Some two score of years before Bacon wrote, in England itself, the great Gilbert of Colchester, who was elected the president of the Royal College of Physicians for the year 1600, and who was physician-in-ordinary to Queen Elizabeth, had applied the experimental method to such good purpose that he well deserves the title that has been conferred upon him of Father of Electricity.
There was never a more purely experimental scientist than Gilbert. His work, De Magnete, is one of the great contributions to experimental science. Anyone who thinks that experiments came only after Lord Bacon's time should read this wonderful work, which is at the foundation of modern electricity. For twenty years, from 1580 to 1600, Gilbert spent all the leisure that he could snatch from his professional duties, in his laboratory. He notes down his experiments his failures as well as his successes discusses them very thoroughly, suggests explanations of success and failure, hits upon methods of control, but pursues the solution of the problems he has in hand ever further and further. As a biographer said of him, " we find him toiling in his workshop at Colchester quite as Faraday toiled, more than two hundred years later, in the low dark rooms of the Royal Institution of Great Britain." Faraday was actuated by no more calm, persevering, inquiring spirit than was Gilbert. To say that any Englishman invented or taught the world the application of the experimental method in science after Gilbert's time is to talk nonsense.
Yet it was of this great scientific observer that Lord Bacon, carried away by ill-feeling and jealousy of a contemporary, went so far as to say in his De Augmentis Scientiarum, that Gilbert " had attempted to found a general system upon the magnet, and endeavored to build a ship out of materials not sufficient to make the rowing-pins of a boat." When Bacon refused to accept Copernicus's teachings, he did not commit a greater error, nor do a greater wrong to mankind, than when he made little of Gilbert of Colchester's work. Poggendorf called Gilbert the " Galileo of Magnetism " and Priestley hailed him as the "founder of modern electricity." When Gilbert did the work on which these titles are founded, however, he was only following out the methods which had been introduced into England long before, and which had been exemplified so thoroughly all during the life of Friar Bacon, and. of Friar Bacon's great teacher, Albertus Magnus. One would expect that at least in science credit would be given properly, and that the false notions introduced by litterateurs and historians of politics should not be allowed to dominate the situation.
The position popularly assigned to Bacon in the history of science is indeed one of those history lies, as the Germans so bluntly but frankly call them, which, though very generally accepted, is entirely due to a lack of knowledge of the state of education and of the progress of scientific investigation long before his time. The reason for this ignorance is the unfortunate tradition which has been so long fostered in educational circles,that nothing worth while ever came out of the Nazareth of the Middle Ages, or the centuries before the so-called reformation and the Renaissance. The ridiculously utter falsity of this impression we shall be able properly to characterize at the end of the next chapter.
As a matter of fact, it would have been much truer to have attributed the origin of experimental science to his great namesake, Roger Bacon, the Franciscan friar, whose work was done at Paris and at Oxford during the latter half of that wonderful thirteenth century that saw the rise and the development of the universities to that condition in which they have practically remained ever since. Even Bacon, however, is not the real originator of the inductive method, since, as we shall see, the writings of his great teacher, the profoundest scholar of this great century, whose years are almost coincident with it, Albert Magnus, the Dominican, who afterwards became Bishop of Ratisbon, contained many distinct and definite anticipations of Bacon as regards the inductive method.
The earlier Bacon, the Franciscan, laid down very distinctly the principle, that only by careful observation and experimental demonstration could any real knowledge with regard to natural phenomena be obtained. He not only laid down the principle, however, but in this, quite a contrast to his later namesake, he followed the route himself very wonderfully. It is for this reason that his name is deservedly attached to many important beginnings in modern science, which we shall have occasion to mention during the course of this and the next chapter. His general attitude of mind toward natural science can be best appreciated from the famous passage with regard to his friend, Petrus Peregrinus, who did such excellent work in magnetism in the thirteenth century, and sent to Friar Bacon the details of it with the loving solicitude of a pupil to a master.
In his Opus Tertium, Bacon thus praises the merits of Peregrinus: "I know of only one person who deserves praise for his work in experimental philosophy, for he does not care for the discourses of men and their wordy warfare, but quietly and diligently pursues the work of wisdom. Therefore, what others grope after blindly, as bats in the evening twilight, this man contemplates in Hence, he knows all of natural science, whether pertaining to medicine and alchemy, or to matters celestial or terrestrial. He has worked diligently in the smelting of ores, as also in the working of minerals ; he is thoroughly acquainted with all sorts of arms and implements used in military service and in hunting, besides which he is skilled in agriculture and in the measurement of lands. It is impossible to write a useful or correct treatise in experimental philosophy without mentioning this man's name. Moreover, he pursues knowledge for its own sake ; for if he wished to obtain royal favor, he could easily find sovereigns who would honor and enrich him."
Brother Potamian's reflections on this unexpected passage of Bacon are the best interpretation of it for the modern student of science.
"This last statement is worthy of the best utterances of the twentieth century. Say what they will, the most ardent pleaders of our day for original work and laboratory methods, cannot surpass the Franciscan monk of the thirteenth century in his denunciation of mere book-learning, or in his advocacy of experiment and research ; while in Peregrinus, the medievalist, they have Bacon's impersonation of what a student of science ought to be. Peregrinus was a hard worker, not a mere theorizer, preferring, Procrusteanlike, to make theory fit the facts rather than facts fit the theory ; he was a brilliant discoverer, who knew at the same time how to use his discoveries for the benefit of mankind ; he was a pioneer of science and a leader in the progress of the world."
This letter of Roger Bacon contains every idea that the modern scientists contend for as significant in education. It counsels observation, not theory, and says very plainly what he thinks of much talk without a basis of observation. It commends a mastery in experiment as the most important thing for science. It suggests, of course, by implication at least, that a man should know all sciences and all applications of them ; but surely no one will object to this medieval friar commending as great a breadth of mental development as possible, as the ideal of an educated man, and especially with regard to the experimental sciences. Finally, it has the surprising phrase, that Peregrinus pursues knowledge for its own sake. Friar Bacon evidently would have sympathized very heartily with Faraday, who at the beginning of the nineteenth century wanted to get out of trade and into science, because he thought it unworthy of man to spend all his life accumulating money, and considered that the only proper aim in life is to add to knowledge. He would have been in cordial accord with Pasteur, at the end of the century, who told the Empress Eugenie, when she asked him if he would not exploit his discoveries in fermentation for the purpose of building up a great brewing industry in France, that he thought it unworthy of a French scientist to devote himself to a mere money making industry.
For a man of the modern time, perhaps the most interesting expression that ever fell from Roger Bacon's lips is his famous proclamation of the reasons why men do not obtain genuine knowledge more rapidly than would seem ought to be the case, from the care and time and amount of work which they have devoted to its cultivation. This expression occurs in Bacon's Opus Tertium, which, it may be recalled, the Franciscan friar wrote at the command of Pope Clement, because the Pope had heard many interesting accounts of all that the great thirteenth century teacher and experimenter was doing at the University of Oxford, and wished to learn for himself the details of his work. Friar Bacon starts out with the principle that there are four grounds of human ignorance.
"These are : first, trust in adequate authority ; second, that force of custom which leads men to accept too unquestioningly what has been accepted before their time ; third, the placing of confidence in the opinion of the inexperienced ; and fourth, the hiding of one's own ignorance with the parade of superficial knowledge." These reasons contain the very essence of the experimental method, and continue to be as important in the twentieth century as they were in the thirteenth. They could only have emanated from an eminently practical mind, accustomed to test by observation and by careful searching of authorities every proposition that came to him.
It is very evident that modem scientists would have more of kinship and intellectual sympathy with Friar Bacon than most of them are apt to think possible. A faithful student of his writings, who was at the same time in many ways a cordial admirer of medievalism, the Iate Professor Henry Morley, who held the chair of English literature at University College, London, whose contributions to the History of English Literature are probably the most important of the nineteenth century, has a striking paragraph with regard to this attitude of Bacon toward knowledge and science two words that have the same meaning etymologically, though they have come to have quite different connotations. Professor Morley, after quoting Bacon's four grounds of human ignorance, said :
"No part of that ground has yet been cut away from beneath the feet of students, although six centuries ago the Oxford friar clearly pointed out its character. We still make sheep walks of second, third and fourth and fiftieth-hand references to authority ; still we are the slaves of habit ; still we are found following too frequently the untaught crowd ; still we flinch from the righteous and wholesome phrase, `I do not know,' and acquiesce actively in the opinion of others, that we know what we appear to know. Substitute honest research, original and independent thought, strict truth in the comparison of only what we really know with what is really known by others, and the strong redoubt of ignorance is fallen."
This attitude of mind of Friar Bacon toward the reasons for ignorance, is so different from what is usually predicated of the Middle Ages and of medieval scholars, that it seems worth while insisting on it. Authority is supposed to have meant everything for the scholastics,and experiment is usually said to have counted for nothing. They are supposed to have been accustomed to swear to the words of the master " jurare in verba magistri " yet here is a great leader of medieval thought insisting on just the opposite. As clearly as ever it was proclaimed, Bacon announces that an authority is worth only the reasons that he advances. These thirteenth century teachers are supposed, above all, to have fairly bowed down and worshipped at the shrine of Aristotle. Many of them doubtless did. In every generation the great mass of mankind must find someone to follow. As often as not, their leaders are much more fallible than Aristotle. Bacon, however, had no undue reverence for Aristotle or anyone else, and he realized that the blind following of Aristotle had done much harm. In his sketch of Gilbert of Colchester, which was published in the "Popular Science Monthly " for August, 1901, Brother Potamian calls attention to this quality of Roger Bacon in a striking passage.
" Roger Bacon, after absorbing the learning of Oxford and Paris, wrote to the reigning Pontiff, Clement IV., urging him to have the works of the Stagirite burnt in order to stop the propagation of error in the schools. The Franciscan monk of Ilchester has left us, in his Opus Majus, a lasting memorial of his practical genius. In the section entitled, " Scientia Experimentalis," he affirms that "Without experiment, nothing can be adequately known. An argument proves theoretically, but does not give the certitude necessary to remove all doubt nor will the mind repose in the clear view of truth, unless it finds it by way of experiment" And in his Opus Tertium : " The strongest arguments prove nothing, so long as the conclusions are not verified by experience. Experimental science is the queen of sciences and the goal of all speculation."
Lest it should be thought that these expressions of laudatory appreciation of the great thirteenth century scientist are dictated more by the desire to magnify his work and to bring out the influence in science of the churchmen of the period, it seems well to quote an expression of opinion from the modern historian of the inductive sciences, whose praise is scarcely if any less outspoken than that of others whom we have quoted and who might be supposed to be somewhat partial in their judgment. This opinion will fortify the doubters who must have authority, and at the same time sums up very excellently the position which Roger Bacon occupies in the history of science.
Dr. Whewell says that Roger Bacon's Opus Majus is "the encyclopedia and Novum Organon of the thirteenth century, a work equally wonderful with regard to its general scheme and to the special treatises with which the outlines of the plans are filled up. The professed object of the work is to urge the necessity of a reform in the mode of philosophizing, to set forth the reasons why knowledge had not made a greater progress, to draw back attention to the sources of knowledge which had been unwisely neglected, to discover other sources which were yet almost untouched, and to animate men in the undertaking by a prospect of the best advantages which it offered. In the development of this plan all the leading portions of science are expanded in the most complete shape which they had at that time assumed ; and improvements of a very wide and striking kind are proposed in some of the principal branches of study. Even if the work had no leading purposes it would have been highly valuable as a treasure of the most solid knowledge and soundest speculations of the time ; even if it had contained no such details, it would have been a work most remarkable for its general views and scope."
The open and inquiring attitude of mind toward the truths of nature is supposed usually to be utterly at variance with the intellectual temper of the Middle Ages. We have heard so much about the submission to authority and the cultivation of tradition on the part of medieval scholars that we forget entirely how much they accomplished in adding to human knowledge, and though they had their limitations of conservatism, they were no more old fogies clinging to old-fashioned ruts than are the older men of each successive generation down even to our own time, in the minds of their younger colleagues. It might seem to be difficult to substantiate such a declaration. It may appear to be a paradox to talk thus. It is not hard to show good reasons for it, and far from being a farfetched attempt to bolster up an opinion more favorable to the Middle Ages, it is really a very simple expression of what the history of these generations shows that they actually tried to accomplish. Roger Bacon must not be thought to be alone in this. On the contrary, he was only a leader with many followers. Even before his time, however, these ideas as to the necessity for observation had been very forcibly expressed by many, and by no one more than Roger's distinguished teacher, Albertus Magnus, whose name is now becoming familiar to scholars as Albert the Great.
Albert's great pupil, Roger Bacon, is rightly looked upon as the true father of inductive science, an honor that history has unfortunately taken from him to confer it undeservedly on his namesake of four centuries later ; but the teaching out of which Roger Bacon was to develop the principles of experimental science can be found in many places in the master's writings. In Albert's tenth book, wherein he catalogues and describes all the trees, plants, and herbs known in his time, he observes: " All that is here set down is the result of our own experience, or has been borrowed from authors whom we know to have written what their personal experience has confirmed : for in these matters experience alone can give certainty "experimentum solum certificat in talibus. "Such an expression," says his biographer, "which might have proceeded from the pen of (Francis) Bacon, argues in itself a prodigious scientific progress, and shows that the medieval friar was on the track so successfully pursued by modern natural philosophy. He had fairly shaken off the shackles which had hitherto tied up discovery, and was the slave neither of Pliny nor of Aristotle."
Albert was a theologian rather than a scientist, and yet, deeply versed as he was in theology, he declared in a treatise concerning Heaven and Earth,' that " in studying nature we have not to enquire how God the Creator may, as He freely wills, use His creatures to work miracles and thereby show forth His power ; we have rather to enquire what nature with its immanent causes can naturally bring to pass." This can scarcely fail to seem a surprising declaration to those who have been accustomed to think of medieval philosophers as turning by preference to miraculous explanations of things, but such a notion is founded partly on false tradition, with regard to the real teaching of the medieval scholars, and even more on the partisan declarations of those who thought it the proper thing to make as little as possible of the intelligence of the people of the Middle Ages, in order to account for their adhesion to the Catholic Church.
As a matter of fact, Albert's declaration, far from being an innovation, was only in pursuance of the truly philosophic method which had characterized the writings of the great Christian thinkers from the earlier time. Unfortunately, the declarations of lesser minds are sometimes accepted as having represented the thoughts of men and the policy of the Church. It is not these lesser men, however, who have been in special honor. No one, for instance, can possibly be looked upon as representing Church teaching better than Augustine, who because of the depth of his teaching, yet his wonderful fidelity to Christian dogma, received the formal title of Father of the Church, which carried with it the approval of everything that he had written. There is a wellknown quotation from St. Augustine which shows how much he deprecated the attempt to make Scriptures an authority in science, and how much he valued observation as compared with authority, in such matters as are really within the domain of investigation by experiment and observation.
He says : "It very often happens that there is some question as to the earth or the sky, or the other elements of this world, respecting which one who is not a Christian has knowledge derived from most certain reasoning or observation " (that is, from the ordinary means at the command of an investigator in natural science), "and it is very disgraceful and mischievous, and of all things to be carefully avoided, that a Christian speaking of such matters as being according to the Christian Scriptures, should be heard by an unbeliever talking such nonsense that the unbeliever, perceiving him to be as wide from the mark as east from west, can hardly restrain himself from laughing." It is the opinions of such men as Augustine and Albert that must be taken as representing the real attitude of theologians and churchmen toward science, and not those of lesser men, whose zeal, as is ever true of the minor adherents of any cause, always is prone to carry them into unfortunate excesses.
Albert the Great was indeed a thoroughgoing experimentalist in the best modern sense of the term. He says in the second book of his treatise On Minerals (De Mineralibus) : "The aim of natural science is not simply to accept the statements of others, that is, what is narrated by people, but to investigate the causes that are at work in nature for themselves." When we take this expression in connection with the other, that " we must endeavor to find out what nature can naturally bring to pass," the complete foundation of experimentalism is laid. Albert held this principle not only in theory, but applied it in practice.
It is often said that the scholastic philosophers, and notably Albertus Magnus and Thomas Aquinas, almost idolatrously worshipped at the shrine of Aristotle, and were ready to accept anything that this great Greek philosopher had taught. We have already quoted Roger Bacon's request to the Pope to forbid the study of the Stagirite. It is interesting to find in this regard, that while Albert declared that in questions of natural science he would prefer to follow Aristotle to St. Augustine a declaration which may seem surprising to many people who have been prone to think that what the Fathers of the Church said medieval scholars followed slavishly he does not hesitate to point out errors made by the Greek philosopher, nor to criticise his conclusions very freely. In his Treatise on Physics,' he says, " whoever believes that Aristotle was a god must also believe that he never erred. But if one believe that Aristotle was a man, then doubtless he was liable to err just as we are." In fact, as is pointed out by the Catholic Encyclopaedia in its article on Albertus Magnus, to which we are indebted for the exact reference of the quotations that we have made, Albert devotes a lengthy chapter in his Summa Theologiae 2 to what he calls the errors of Aristotle. His appreciation of Aristotle is always critical. He de-serves great credit not only for bringing the scientific teaching of the Stagirite to the attention of medieval scholars, but also for indicating the method and the spirit in which that teaching was to be received.
With regard to Albert's devotion to the experimental method and to observation as the source of knowledge in what concerns natural phenomena, Julius Pagel, in his History of Medicine in the Middle Ages, which forms one of the parts of Puschmann's Handbook of the History of Medicine, has some very interesting remarks that are worth while quoting here : " Albert, " he says, " shared with the naturalists of the scholastic period the quality of entering deeply and thoroughly into the objects of nature, and was not content with bare superficial details concerning them, which many of the writers of the period penetrated no further than to provide a nomenclature. While Albert was a churchman and an ardent devotee of Aristotle in matters of natural phenomena, he was relatively unprejudiced and presented an open mind. He thought that he must follow Hippocrates and Galen rather than Aristotle and Augustine in medicine and in the natural sciences. We must concede it as a special subject of praise for Albert, that he distinguished very strictly between natural and supernatural phenomena. The former he considered as entirely the object of the investigation of nature. The latter he handed over to the realm of metaphysics."
"Albert's efforts, Pagel says, to set down the limits of natural science shows already the seeds of a more scientific treatment of natural phenomena, and a recognition of the necessity to know things in their causes rerum cognoscere causas and not to consider that everything must simply be attributed to the action of Providence. He must be considered as one of the more rational thinkers of his time, though the fetters of scholasticism still bound him quite enough, and his mastery of dialectics, which he had learned from the strenuous Dominican standpoint, still made him subordinate the laws of nature to the Church's teaching in ways that suggested the possibility of his being less free than might otherwise have been the case. His thoroughgoing piety, his profound scholarship, his boundless industry ; the almost uncontrollable impulse of his mind after universality of knowledge ; his many sidedness in literary productivity ; and finally the universal recognition which he received from his contemporaries and succeeding generations, stamp him as one of the most imposing characters and one of the most wonderful phenomena of the Middle Ages."
Perhaps in no department of the history of science has more nonsense been talked, than with regard to the neglect of experiment and observation in the Middle Ages. The men who made the series of experiments necessary to enable them to raise the magnificent Gothic cathedrals ; who built the fine old municipal buildings and abbeys and castles ; who spanned wide rivers with bridges, and yet had the intelligence and the skill to decorate all of these buildings as effectively as they did, cannot be considered either as impractical or lacking in powers of observation. As I show in the chapter The Medieval University Man and Science, Dante, the poet and literary man of the thirteenth century, had his mind stored with quite as much material information with regard to physical science and nature study, as any modern educated man. It is true that the men of the Middle Ages did not make observations on exactly the same things that we do, but to say either that they lacked powers of observation, or did not use their powers or failed to appreciate the value of such powers, is simply a display of ignorance of what they actually did.
On the other hand, when it comes to the question of the principles of experimental science and the value they placed on them, these men of the medieval universities, when sympathetically studied, prove to have been quite as sensible as the scientists of our own time. The idea that Francis Bacon in any way laid the foundation of the experimental sciences, or indeed did anything more than give a literary statement of the philosophy of the experimental science, though he himself proved utterly unable to apply the principles that he discussed to the scientific discoveries of his own time, is one of the inexplicable absurdities of history that somehow get in and cannot be got out. The great thinkers of the medieval period had not only reached the same conclusions as he did, but actually applied them three centuries before ; and the great medieval universities were occupied with problems, even in physical science, not very different from those which have given food for thought for subsequent generations. We shall see in the next chapter how successfully they applied these great principles of the experimental method, and how much they anticipated many phases of science that we are apt to think of as distinctly modern.