Bacon’s criticisms have usually been taken to apply to medieval learning as a whole, but a closer examination shows their application to be much more limited. In the first place, he is thinking only of the past “forty years” in making his complaints; in the good old days of Grosseteste, Adam Marsh, William Wolf, and William of Shyrwood things were different, and scholarship flowed smoothly, if not copiously, in the channels marked out by the ancient sages;[2109] nor does Bacon deny that there was a renaissance of natural science and an independent scientific spirit still farther back in the twelfth century.
Secondly, except for his tirades against the Italians and their civil law, Bacon’s criticisms apply to but two countries, France and England, and two universities, Oxford and Paris. Also those few contemporaries whom he praises are either his old Oxford friends or scattered individuals in France. Of the state of learning in Italy, Spain, and Germany he says little and apparently knew little. Amid his sighing for some prince or prelate to play the patron to science, he never mentions Alfonso X of Castile, who was so interested in the “mathematics” and occult science which were so dear to Bacon’s heart;[2110] Roger even still employs the old Toletan astronomical tables of Arzachel instead of the Alfonsine tables issued in 1252, the first year of that monarch’s reign.[2111] His lamentation over the sad neglect of astrology among the “Latins” is not borne out by our investigations of their interest in that subject, and indicates that he was ignorant of the work at the University of Bologna of the astrologer, Guido Bonatti, whose voluminous Latin treatise on that art based on wide reading in both classical and Arabian scholars did not indeed appear until after 1277,[2112] but must have already been in preparation when Bacon wrote, since Guido was born at some time before 1223.[2113] Bacon grieves at the neglect of the science of optic by his age, and says that it has not yet been lectured on at Paris nor elsewhere among the Latins except twice at Oxford;[2114] he does not mention the Pole, Witelo, who traveled in Italy and whose important treatise on the subject was produced at about this time.[2115]
While complaining of the ignorance of the natures and properties of animals, plants, and minerals which is shown by contemporary theologians in their explanation of Scriptural passages, Bacon not only slights the encyclopedias which several clergymen like Alexander Neckam, Bartholomew of England, Thomas of Cantimpré and Vincent of Beauvais had compiled; he also says nothing of the school at Cologne of Albertus Magnus, whose reputation was already established by the middle of the century, who personally investigated many animals, especially those of the north, and often rectified the erroneous assertions of classical zoologists, whom the historian of botany has lauded, whose students too were curious to know not only the theoretical botany that passed under the name of Aristotle, but also the particular characteristics of plants, and who in his five books on minerals discusses the alchemy and indulges in the same occult science and astrology which Bacon deemed so important. Yet Albert was a noted theologian and Biblical commentator as well as a student of nature.
In saying that Bacon does not mention Albert’s work in natural science, I of course do not mean to imply that he never mentions Albert. He excuses his delay in answering the pope by declaring that the most noted Christian scholars, such as Brother Albert of the Order of Preachers, and Master William of Shyrwood, could not in ten years produce such a work as he transmits; and he incidentally observes that William is a far abler scholar than Albert.[2116] I am suspicious, however, of the integrity of the passage[2117] where Bacon sneers at the theological teaching of “the boys of the two Orders, such as Albert and Thomas and the others who enter the Orders when twenty years or under.” It seems incongruous for Bacon to speak of his probable senior, Albert, as a boy. Other passages in Bacon’s works which have been taken to apply to Albert, though he is not expressly named, seem to me not to apply to him at all closely; and if meant for him, they show that Bacon was an incompetent and unfair critic. Not only was Albert only for a short time in Paris; he does not seem to have been in sympathy with the conditions there which Bacon attacks. Nor can I see that Bacon is meant in the passage at the close of Albert’s Politics,[2118] where he declares that its doctrines, as in his books on physics, are not his own theories but a faithful reflection of peripatetic opinion; and that he makes this statement for the benefit of lazy persons who occupy their idle hours in searching writings for things to criticize; “Such men killed Socrates, drove Plato from Athens to the Academy, and, plotting even against Aristotle, forced him into exile.” Such a passage seems a commonplace one. Both Adelard of Bath and William of Conches expressed the same fear of setting forth new ideas of their own, and medieval writers not infrequently in their prefaces apprehend with shrinking “the bite of envy” which both their Horace and personal experience had taught would follow fast on publication.
Thirdly, while Bacon occasionally makes bitter remarks about the present state of learning in general, it is the teaching of theology at Paris and by the friars that he has most in mind and that he especially desires to reform. Though himself a friar and master of theology, he had been trained and had then himself specialized in the three learned languages, Hebrew, Greek and Arabic, in optic and geometry, in astronomy and astrology, in alchemy and “experimental science,” and in the writings of the classical moralists. Consequently he thought that no one could be a thorough theologian who did not go through the same course of training; nay, it was enough to ruin the reputation of any supposed scholar in Bacon’s sight, if he were unacquainted with these indispensable subjects. Bacon held that it was not sufficient preparation for theology merely to study “the common sciences, such as Latin, grammar, logic, and a part of natural philosophy, and a little metaphysics.”[2119] However, it was not that he objected to these studies in themselves, nor to the ordinary university instruction in the arts course; in fact, he complains that many young friars start in to study theology at once and “presume to investigate philosophy by themselves without a teacher.”[2120] Bacon has a low opinion of the scholarship of Alexander of Hales, because his university education had been completed before the chief authorities and commentaries in natural philosophy and metaphysics had been translated. Against another friar generally regarded by the academic world as its greatest living authority Bacon brings the charge that “he never heard philosophy in the schools,” and “was not instructed nor trained in listening, reading and disputing, so that he must be ignorant of the common sciences.”[2121] Such passages show that to represent Bacon’s writings as full of “sweeping attacks” upon “the metaphysical subtleties and verbal strifes” of his age is to exaggerate his position.[2122] There are not many direct attacks upon scholastic method in his works.
It is true that Bacon complains of the lack of good teachers in his day, saying in the Opus Minus that he could impart to an apt pupil in four years all the knowledge that it had taken himself forty years to acquire,[2123] and in the Opus Tertium that he could do it in a half or a quarter of a year, and that he could teach a good student all the Greek and Hebrew he need know in three days for each subject.[2124] But aside from the young friars who presume to teach theology, the teachers against whom he rails most are those in his favorite subject of “mathematics.” Bacon could teach more useful geometry in a fortnight than they do in ten or twenty years[2125]—a hint that much time was given in those days to the study of mathematics. These boasts are not, however, as wild as they may at first seem; after all Roger did not know a vast amount of geometry and Greek and Hebrew, and he had no intention of teaching any more of mathematics and the languages than would be of service in his other sciences, in theology, and in practical life. He complained that “the ordinary mathematician does not consider that he knows anything unless he demonstrates it, and so he takes from thirty to forty years” to master the subject, and that “the text-books and the teachers of mathematics delight in multiplying conclusions to such an extent that one has to give years of unnecessary time to extracting the essentials,” and “this is one reason why there are so few students of a science which is a prerequisite to all knowledge.”[2126] Nor were such boasts unique in the age in which Bacon lived. Another professor and Franciscan friar, who wrote at least no later than the early fourteenth century, Bernard of Verdun, states that his little book on astronomy takes the place of “innumerable works and huge tomes,” and makes it possible for anyone acquainted with geometry to learn in a short time not only the gist of books which two years of steady reading could scarce suffice to cover, but also many points which other books omit.[2127]
It is easy to discern the personal motives which actuated Bacon in his criticism. He was jealous of his more successful contemporaries and desperately anxious to secure the pope as his patron. If, as Macaulay said, Francis Bacon seeking the truth was a very different person from Francis Bacon seeking the seals, we must remember that Roger Bacon combined both attempts at once. He grieved to see the neglect by his fellow theologians of the subjects in which he was particularly interested, and to see himself second in reputation, influence and advancement to the “boy theologians.” It angered him that these same narrowly educated and narrow-minded men should “always teach against these sciences in their lectures, sermons and conferences.”[2128] And after all, as he tells the pope, he does not wish to revolutionize the curriculum nor overthrow the existing educational system, “but that from the table of the Lord, heaped with wisdom’s spoils, I, poor fellow, may gather the falling crumbs I need.”
Bacon’s allusions to and dates for events in the history of medieval learning are sometimes hard to fit in with what we learn from other sources, and as we have seen he has been detected in misstatements of the doctrines of other scholars.[2129] His personal diatribes against the Latin translators of Greek and Arabian science seem overdrawn and unfair, especially when he condemns the first translators for not knowing the sciences in question before they ventured to translate, whereas it is plain that the sciences could not be known to the Latin world until the translations had been made. Indeed, it may be doubted if Roger himself knew Arabic well enough to read scientific works therein without a translation or interpreter. Especially unjustifiable and ill advised seems his savage onslaught upon William of Moerbeke,[2130] whom we are told Aquinas induced to translate Aristotle from the Greek, who was like Bacon interested in occult science, and to whom Witelo dedicated his treatise on optics. As William held the confidential post of papal chaplain and penitentiary under Clement IV, and as he became archbishop of Corinth about the time that Roger was condemned to prison, there may have been some personal rivalry and bitterness between them.
It should be said to Bacon’s credit that his own statements do not support the inference which others have drawn from them, that he was alone in the advocacy or pursuit of the studies dear to him. In the Opus Minus he says to the pope, with rather unusual modesty it must be admitted, “I confess that there are several men who can present to Your Wisdom in a better way than I can these very subjects of which I treat.”[2131] And though the secrets of the arts and sciences are neglected by the crowd of students and their masters, “God always has reserved some sages who know all the necessary elements of wisdom. Not that anyone of them knows every detail, however, nor the majority of them; but one knows one subject, another another, so that the knowledge of such sages ought to be combined.”[2132] Combine it Bacon does for the pope’s perusal, and he is not ashamed to speak on its behalf, for though there are fewer Latins conversant with it than there should be, there are many who would gladly receive it, if they were taught.[2133] Thus he speaks not merely as an exponent of his own ideas, but as the representative of a movement with a considerable following at least outside of strictly theological circles.
Bacon has been given great credit for pointing out the need of calendar revision three centuries before the papacy achieved it; but he says himself that not only wise astronomers but even ordinary computistae were already aware of the crying need for reform,[2134] and his discussion of the calendar often coincides verbally with Grosseteste’s Computus.[2135] When Cardinal Pierre d’Ailly over a century later again urged the need of reform upon Pope John XXIII he cited Grosseteste often, but Bacon seldom or never.[2136] The Parisian version of the Bible, against which Bacon inveighs as a corruption of the Vulgate, was in the first instance the work of a conscientious Hebrew scholar;[2137] and the numerous corrections and changes made in it since, though deplored by Bacon, show the prevalent interest in such matters. While Bacon holds that there are very few men who understand the theory of Greek, Hebrew and Arabic grammar, or the technique of the sciences which have to be studied from those languages, he admits that many men are found among the “Latins” who can speak those tongues and that there are even plenty of teachers of Greek and Hebrew at Paris and elsewhere in France and England.[2138] Thus Bacon was not so superior linguistically to his age as he has sometimes been depicted.
The treatment of geography in the Opus Maius is simply an intelligent compilation of well-known past writers, including the wretched work of Ethicus, supplemented from writings of the friars who had recently visited the Tartars. Roger Bacon’s name has sometimes been connected with the discovery of America by Columbus on the ground that Columbus was greatly influenced by the Imago mundi of Pierre d’Ailly and that a chapter in that work on the extent of the habitable earth was copied in large measure without acknowledgment from Roger Bacon.[2139] Cardinal d’Ailly, however, can scarcely be censured for failing to mention Bacon in this context since he does cite him elsewhere and since in this passage all that he borrows from Roger are the statements of other writers whom Roger cites. That is, against Ptolemy’s discouraging assertion that five-sixths of the earth’s surface is covered with water he cites Aristotle, Seneca and Pliny to prove that the distance west from Spain to India is not great and the apocryphal book of Esdras to the effect that only one-seventh of the earth’s surface is covered with water. But it is contended that the Imago Mundi was not published until 1487[2140] and that Columbus did not read it until after his first voyage in 1492,[2141] which is to be regarded as a continuation of the search after new islands and lands in the western ocean already undertaken by various Portuguese sailors.[2142] It is interesting to note one argument for the propinquity of northwestern Africa to India employed by Bacon which d’Ailly, firm believer in astrology as he was, did not copy. Bacon argues that Aristotle and his commentator included northwestern Africa in “Spain,” “since they say as proof of the narrowness of the sea between Spain and India that there are elephants only in those two places.” And “Aristotle says that there cannot be elephants in those places unless they were of like complexion.”[2143]—i. e., under the same constellations.
If in many respects Bacon’s contribution to learning has been overestimated, there is one side of his thought which has seldom been emphasized but deserves some notice, namely, his historical attitude. In one sense history was a weak point with Bacon as with most of his contemporaries. He not only accepted the faulty accounts of the past current in his day, but was apt to pounce upon the most sensational and incredible details and use these to support his case. He had no notion of historical criticism. Unfortunately he thought that he knew a good deal about the history of philosophy, and his attitude to science is colored by his false ideas of the history of intellectual development. He of course knew nothing of evolution or of prehistoric man. For him intellectual history commenced with a complete divine revelation of philosophy to the patriarchs. Science then declined owing to the sinfulness of mankind, the invention of magic by Zoroaster, and further corruption of wisdom at the hands of Nimrod, Atlas, Prometheus, Hermes Trismegistus, Aesculapius, and Apollo. Complete knowledge and understanding were granted again by God to Solomon, after whom succeeded another period of sinful decline, until with Thales began the gradual upbuilding of Greek philosophy culminating in Aristotle. Then night set in again, until Avicenna revived philosophy among the Arabs. To him and Aristotle, however, as infidels, less complete knowledge was vouchsafed than to the representatives of God’s chosen people.[2144] Of the composition and development of Roman law Bacon had so little notion that he thought it borrowed chiefly from Aristotle and Theophrastus, except that the Twelve Tables were derived from the laws of Solon.[2145] Though he saw the value of linguistics and textual criticism, and sought with true humanistic ardor for a lost work like the Morals of Seneca, he accepted as genuine works of antiquity spurious treatises like the De Vetula ascribed to Ovid.[2146] He believed that Paul had corresponded with Seneca and that Alexander’s conquests were due to Aristotle’s experimental science. We shall soon see how he used the astrological interpretation of history, which was the medieval counterpart of our geographical and economic interpretation. Yet Bacon deserves praise for so often opening his discussion of a problem by an inquiry into its historical background; he at least tried to adopt the historical point of view. And on the whole his historical method makes about as close an approach to modern research as do his mathematics and experimental science to their modern parallels.
Yet the introduction of mathematical method into natural science has often been attributed to Roger Bacon, in which respect he has been favorably contrasted with Francis Bacon. Therefore it will be well to note exactly what Roger says on this point and whether his observations were notably in advance of the thought of his times. It will be recalled that in his criticism of the teaching of mathematics Roger had shown little appreciation of the labors of those pure mathematicians who devoted a lifetime to painstaking demonstration and were satisfied with nothing short of it. The discussion in the Opus Maius opens with strong assertions of the necessity for a knowledge of mathematics in the study of natural science and of theology as well; and we are told that neglect of mathematics for the past thirty or forty years has been the ruin of Latin learning. This position is supported by citation of various authorities and by some vague general arguments in typical scholastic style. Grammar and logic must employ music, a branch of mathematics, in prosody and persuasive periods. The categories of time, place, and quantity require mathematical knowledge for their comprehension. Mathematics must underlie other subjects because it is by nature the most elementary and the easiest to learn and the first discovered. Moreover, all our sense knowledge is received in space, in time, and quantitatively. Also the certitude of mathematics makes it desirable that other studies avail themselves of its aid.
But now we come to the application of these glittering generalities and we see what Bacon’s “mathematical method” really amounts to. Briefly, it consists in expounding his physical and astronomical theories by means of simple geometrical diagrams. The atomical doctrine of Democritus cannot be true, since it involves the error that the hypothenuse is of the same length as the side of a square. Geometry satisfies Roger that there can be but one universe; otherwise we should have a vacuum left. Plato’s assertion that the heavens and four elements are made up each of one group of regular solids is also subjected to geometrical scrutiny. Mathematics is further of service in Biblical geography, in sacred chronology, and in allegorical interpretation of the dimensions of the ark, temple, and tabernacle, and of various numbers which occur in Scripture. But mathematics, according to Bacon, plays its greatest rôle in astronomy or astrology and in physics, and in his favorite theory of multiplication of species or virtues, or, as modern writers have flatteringly termed it, the propagation of force.[2147]
Astronomy and astrology had together long made up the world’s supreme science; there was no originality in urging their importance, and unfortunately it was astrology rather than astronomy which seemed to Bacon by far the most important and practical part of mathematics. In physics he borrowed his discussion of weights and falling bodies from Jordanus, an earlier writer in the thirteenth century, and his optics from Alhazen and Grosseteste and from treatises which passed then under the names of Ptolemy and Euclid but were perhaps of more recent origin.[2148] Bacon’s graphic expression of the multiplication of species by lines and figures we find earlier in Grosseteste’s De Lineis, Angulis, et Figuris.[2149] It does not seem, therefore, that Bacon made any new suggestions of great importance concerning the application of mathematical method in the sciences, and historians of mathematics have recognized that “he contributed nothing to the pure science,”[2150] of whose very meaning his notion was inadequate.
Let us next inquire what contributions, if any, Bacon made in the direction of modern experimental method. Jebb’s edition of the Opus Maius in 1733 ended with the sixth part on “Experimental Science,” which thus received undue prominence and seemed the climax of the work. Bridges’ edition added the seventh part on “Moral Philosophy,” “a science better than all the preceding,” and the text as now extant, after listing various arguments for the superiority of Christianity to other religions, concludes abruptly with an eight-page devout justification and glorification of the mystery of the Eucharist.
Our preceding chapters have similarly rectified the place of Bacon’s discussion of experimental science in the history of thought. We have already brought out the fact that he was not the first medieval man to advocate experimentation, but that writers before him contain “experiments,” rely on experience rather than mere authority, and mention the existence of other “experimenters” and “experimental books.” We have noted Petrus Hispanus’ discussion of “the experimental method” (via experiment), Albertus Magnus’ experimental school for the study of nature, Robert Grosseteste’s association of experimentation with physics, and William of Auvergne’s association of experiment with natural magic. We have described experiments of Constantinus Africanus, Adelard of Bath, Pedro Alfonso, Bernard Silvester, and many others. We have yet to describe experimental books, many of which antedate Roger Bacon. His discussion will be found to do little more than duplicate and reinforce the picture of the medieval status of experimental method which we have already obtained from other and earlier sources. He is not a lone herald of the experimental method of modern science; he merely reveals and himself represents the merits and the defects of an important movement of his time.
Bacon’s discussion of “experimental science” and of experimental method are not quite one and the same thing. He treats of “experimental science” in a separate section of the Opus Maius, and seems to regard it as something distinct from his other natural sciences, such as optics, alchemy, astronomy and astrology, rather than as an inductive method through regulated and purposive observation and experience to the discovery of truth, which should underlie and form an essential part of them all. Yet he also approaches the latter conception. But note that, while the sixth part on “Experimental Science” is not the last section of the Opus Maius, it is the last of the natural sciences to be discussed by him there rather than the first. It is not, like modern experimentation, the source but “the goal of all speculation.” It is not so much an inductive method of discovering scientific truth, as it is applied science, the putting the results of the “speculative” natural sciences to the test of practical utility. “Other sciences know how to discover their first principles through experience, but reach their conclusions by arguments made from the principles so discovered. But if they require a specific and final test of their conclusions, then they ought to avail themselves of the aid of this noble science.”[2151] “Natural philosophy narrates and argues but does not experiment. The student of perspective and the astronomer put many things to the test of experience, but not all nor sufficiently. Hence complete experience is reserved for this science.”[2152] It uses the other sciences to achieve definite practical results; as a navigator orders a carpenter to build him a ship or a knight tells a smith to make him a suit of armor, so the experimentator uses his knowledge of geometry to construct a burning-glass or outdoes alchemy at its own specialty of gold-making.[2153] In working out these practical inventions, however, the “experimenter” often happens on new facts and truths of which the speculative sciences have not dreamed, and in this way experimental science “by its own power investigates the secrets of nature.” Thus Bacon begins to see the advisability of a close alliance between “experimental science” and natural science, but it is also clear that they are not yet identified. The artisans of the gilds and the alchemists—Bacon includes a discussion of alchemy in the same sixth section with his “experimental science,” although in a way keeping the two distinct—seem to be engaging in this experimental science more than do the scholars of the books and schools. As William of Auvergne associated experimentation with magic rather than with science, so Bacon seems to regard natural science as largely speculative, and confirms the impression, which we have already derived from many other sources, that magicians were the first to “experiment,” and that “science,” originally speculative, has gradually taken over the experimental method from magic. This impression will be strengthened as we proceed to examine in more detail, first Bacon’s “experimental science” and then what he has to say concerning magic. From now on, however, we shall credit Bacon with all the traces of experimental method that we can find anywhere in his writings, as well as in his separate section on “experimental science” in the Opus Maius and his further allusions to the same subject in the Opus Minus and Opus Tertium.
Bacon not merely emphasizes the importance of experience in arriving at the truth, but of all sciences regards his “experimental science” as the best criterion of truth. “All sciences except this either merely employ arguments to prove their conclusions, like the purely speculative sciences, or have universal and imperfect experiences”;[2154] while “It alone, in truth, has the means of finding out to perfection what can be done by nature, what by the industry of art, what by fraud”; for it alone can distinguish what is true from what is false in “incantations, conjurations, invocations, deprecations, and sacrifices.”[2155]
But how is one to set about experimenting? On this point Bacon is disappointing. His explanation of the rainbow, which is his longest illustration of the value of experimental science, is based merely on ordinary intelligent observation and reasoning, although he adds at the close that tests with instruments are needed and that consequently he will not assert that he has reached the full truth of the matter.[2156] Elsewhere he speaks of astronomical experiments “by instruments made for this purpose,” but seems to regard the unaided eyesight as sufficient for the investigation of terrestrial phenomena. Bacon has sent “over sea and to various other lands and to annual fairs, in order that I might see the things of nature with my own eyes.”[2157] “And those things which are not present in our locality we may know through other sages who have experienced them, just as Aristotle by authority of Alexander sent two thousand men to different regions to experience all things on the face of the earth, as Pliny testifies in his Natural History.”[2158] The one contemporary who most nearly fulfills Bacon’s ideal of what an experimental scientist should be, does not spend his time merely in reading, attending lectures, and engaging in disputations, but “is ashamed to have some layman or old wife or knight or rustic know facts of which he is ignorant”; hence he goes out into the world and observes the doings of common workingmen and even takes hints from the operations of witches, enchanters and magicians.[2159] Bacon even accepts the notion which we have already often met in other writers, that valuable medicines can be discovered by observing what remedies various animals employ. It would seem that experimental method is in a low state of its development, if it takes lessons from common human experience and from the actions of brutes. Bacon sufficiently indicates, however, that it does not consist merely of observation and casual experience, but includes purposive experimentation, and he often speaks of “experimenters.” Undoubtedly he himself experimented. But the fact remains that he gives no directions concerning either the proper environment for experimenting or the proper conduct of experiments. Of laboratory equipment, of scientific instruments, of exact measurements, he has no more notion apparently than his contemporaries.
It cannot be shown that Roger Bacon actually anticipated any of our modern inventions, nor that to him in particular were due any of the medieval inventions which revolutionized domestic life such as chimney flues and window panes, or navigation such as the rudder and mariner’s compass, or public and ecclesiastical architecture such as the pointed vault and flying buttress and stained glass, or reckoning and writing such as the Hindu-Arabic numerals and paper, or reading and seeing such as lenses and eye-glasses, or warfare such as gunpowder.[2160] We probably are justified, however, in accepting such passages in his works as the following, not merely as dreams that have been brought true by modern mechanical inventions, but as further indications that an interest existed in mechanical devices, and that men were already beginning to struggle with the problems which have recently been solved.
“Machines for navigation can be made without rowers so that the largest ships on rivers or seas will be moved by a single man in charge with greater velocity than if they were full of men. Also cars can be made so that without animals they will move with unbelievable rapidity; such we opine were the scythe-bearing chariots with which the men of old fought. Also flying machines can be constructed so that a man sits in the midst of the machine revolving some engine by which artificial wings are made to beat the air like a flying bird. Also a machine small in size for raising or lowering enormous weights, than which nothing is more useful in emergencies. For by a machine three fingers high and wide and of less size a man could free himself and his friends from all danger of prison and rise and descend. Also a machine can easily be made by which one man can draw a thousand to himself by violence against their wills, and attract other things in like manner. Also machines can be made for walking in the sea and rivers, even to the bottom without danger. For Alexander the Great employed such, that he might see the secrets of the deep, as Ethicus the astronomer tells. These machines were made in antiquity and they have certainly been made in our times, except possibly a flying machine which I have not seen nor do I know any one who has, but I know an expert who has thought out the way to make one. And such things can be made almost without limit, for instance, bridges across rivers without piers or other supports, and mechanisms, and unheard of engines.”[2161] Since Bacon’s authority concerning Alexander is unreliable and his conjectures concerning ancient scythe-bearing chariots unwarranted, we may also doubt if steamboats and automobiles had “certainly been made” in his day; but men may have been trying to accomplish such things.
Bacon says far more of the marvelous results which he expects experimental science to achieve than he does of the methods by which such results are to be attained. In the main marvelousness rather than practicability characterizes the aims which he proposes for scientia experimentalis. Indeed, of the three ways in which he represents it as superior to all other sciences, while one is that it employs sure proofs rather than mere arguments, two are that by it life may be greatly lengthened, and that from it a better knowledge of the future may be gained than even from astrology.[2162] Thus experimental method is especially connected with alchemy and astrology. Bacon declares that “it has been proved by certain experiments” that life can be greatly prolonged “by secret experiences.”[2163] and he believes that Artephius was enabled by such methods to live for a thousand and twenty-five years.[2164] Or experimental science may predict the weather by observing the behavior of animals.[2165]
Some of Bacon’s “experiments” are as fantastic as the aims are marvelous. “A good experimenter says in the book De regimine senum” that the following elixir will greatly prolong life: “that which is temperate in the fourth degree, and what swims in the sea, and what grows in the air, and what is cast up by the sea, and plant of India, and what is found in the entrails of an animal of long life, and those two serpents which are the food of the inhabitants of Tyre and Ethiopia.”[2166] We also are told that “at Paris recently there was a sage who asked for snakes and was given one and cut it into small sections except that the skin of its belly on which it crawled remained intact; and that snake crawled as best it could to a certain herb by touching which it was instantly made whole. And the experimenter collected an herb of wonderful virtue.”[2167]
Credulity, in contrast to the sceptical attitude of modern science is a characteristic of Bacon’s experimental method. He declares, it is true, that experiment disproves many false notions such as that hot water freezes faster than cold, that adamant can be broken only with the blood of a goat, and that the beaver when hunted castrates itself to save its life;[2168] but we have already heard such beliefs questioned by Albertus Magnus and others. On the other hand, Bacon asserts that credulity is necessary to experimentation. “First one should be credulous until experience follows second and reason comes third.... At first one should believe those who have made experiments or who have faithful testimony from others who have done so, nor should one reject the truth because he is ignorant of it and because he has no argument for it.”[2169] Taken as a plea for an open-minded attitude toward scientific investigation on the part of the ordinary man and of the ecclesiastical authorities, this utterance may be commended; but as a prescription for the scientific investigator it is dangerous. Many of Bacon’s “experiments” are copied from books, and the reproach made against the Greek Empirics that they followed tradition, applies also to him. Describing a certain marvel of nature, he exclaims, “After I beheld this, there was nothing difficult for my mind to believe, provided it had a reliable author.”[2170] In the midst of his discussion of experimental science we encounter the following instance of his gullibility: