method would, incidentally, tend to equalise intellectual capacities1 so that all minds who followed it with care and patience would be able to find truth and use it for fruitful works. "It is a correct position," says Bacon, “that true knowledge is knowledge by causes." But the way in which he understands this position is significant. He adopts the Aristotelian division of causes into four kinds: material, formal, efficient, and final. Physic deals with the efficient and material causes; but these, apart from their relation to the formal cause, are but slight and superficial, and contribute little, if anything, to true and active science.' The enquiry into the other two belongs to that branch of natural philosophy which he calls metaphysic. "But of these the final cause rather corrupts than advances the sciences, except such as have to do with human action," and "the discovery of the formal is dispaired of 2." Yet forms must be investigated if nature is to be understood and controlled. Thus the second book of the Novum Organum opens with the aphorism, "On a given body to generate and superinduce a new nature is the work and aim of human power. Of a given nature to discover the form... is the work and aim of human knowledge." is What, then, does Bacon mean by 'form'? He gives many answers to this question, and yet the meaning not altogether easy to grasp. Form is not something mental; it is not an idea, nor is it a mere abstraction; it is itself physical. According to Bacon, nothing really exists in nature except individual bodies. But the 'forms of substances' are so complicated that their investigation, if possible at all, must be postponed until enquiry has been made into forms of a simpler kind-those of the qualities or natures' possessed by substances3. The form is the condition or ground of these natures: its presence determines the presence of the relative nature; 1 N.O., 1, 61. 2 N.O., 11, 2; cp. Works, 1, p. 364, iv, p. 360. 3 De Augmentis, 111, 4; Works, 1, p. 365. with its absence the nature vanishes; further, a true form deduces the given nature from some source of being or essence which is inherent in many different things1. Thus the form would seem to be expressed by a definition per genus et differentiam. This explanation, however, is supplemented by another which identifies form with law. "When I speak of forms," he says, “I mean nothing more than those laws and determinations of absolute actuality which govern and constitute any simple nature, as heat, light, weight, in every kind of matter and subject that is susceptible of them. Thus the form of heat or the form of light is the same thing as the law of heat or the law of light." And again, "The form of a thing is the very thing itself, and the thing differs from the form no otherwise than as the apparent differs from the real, or the external from the internal, or the thing in reference to man from the thing in reference to the universe3" The complexity of the physical universe is due to the combination, in varied ways, of a limited number of forms which are manifested to us in sensible qualities. If we know the form, we know what must be done to superinduce the quality upon a given body. Hence the practical character of Bacon's theory. Here also is brought out an idea that lies at the basis of his speculative doctrine— the idea that the forms are limited in number. They are, as it were, the alphabet of nature; when they are understood, the whole language will be clear. Philosophy is not an indefinite striving after an ever-receding goal. Its completion may be expected in the near future, if only the appropriate method is followed. The new method leads to certainty. Bacon is almost as contemptuous of the old induction, which proceeded from a few experiments to general laws, as he is of the syllogism. His new induction is to advance by gradual 1 N.O., 11, 4; cp. Fowler's edition, 2nd ed., pp. 54 f. stages of increasing generality, and it is to be based on an exhaustive collection of instances. This collection of instances is the work of what Bacon called natural history, and he laboured to give specimens of the collections required. He always recognised that the collaboration of other workers was needed for their completion and that the work would take time. His sense of its magnitude seems to have deepened as it progressed; but he never realised that the constant process of development in nature made an exhaustive collection of instances a thing impossible. Given the requisite collection of instances, the inductive method may be employed without risk of error. For the form is always present where the nature (or sensible quality) is present, absent where it is absent and increases or decreases with it. The first list of instances will consist of cases in which the nature is present: this is called the table of essence and presence. Next come the instances most akin to these in which nevertheless the nature is absent: this is called the table of absence in proximity. Thirdly, a list is made of instances in which the nature is found in different degrees, and this is the table of degrees or comparison. True induction begins here, and consists in a 'rejection or exclusion' of the several natures which do not agree in these respects with the nature under investigation. The non-essential are eliminated; and, provided our instances are complete and our notions of the different natures adequate, the elimination will proceed with mechanical precision. Bacon saw, however, that the way was more intricate than this statement suggests-especially owing to the initial difficulty of getting sound and true notions of simple natures1. Aids therefore must be provided. In the first place, he will allow the understanding to essay the interpretation of nature on the strength of the instances given. This " commencement of interpretation," which, to some extent, plays the part of 1 N.O., II, 19. hypothesis (otherwise absent from his method), receives the quaint designation of First Vintage. Other helps are then enumerated which Bacon proposes to treat under nine heads: prerogative instances; supports of induction; rectification of induction; varying the investigation according to the nature of the subject; prerogative natures (or what should be enquired first and what last); limits of investigation (or a synopsis of all natures in the universe); application to practise; preparations for investigation; ascending and descending scale of axioms. Only as regards the first of these is the plan carried out. The remainder of the Novum Organum is taken up with the discussion of twenty-seven kinds of prerogative instances; and here are to be found many of his most valuable suggestions, such as his discussion of solitary instances and of crucial instances. Although the new method was never expounded in its completeness, it is possible to form a judgment on its value. In spite of the importance and truth of the general ideas on which it rests, it has two serious defects, of which Bacon himself was not unaware. It gives no security for the validity and accuracy of the conceptions with which the investigator works, and it requires a complete collection of instances, which, in the nature of things, is impossible. Coupled with these defects, and resulting from them, are Bacon's misunderstanding of the true nature and function of hypothesis, upon which all scientific advances depend, and his condemnation of the deductive method, which is an essential instrument in experimental verification. The method of scientific discovery and proof cannot be reduced to the formulae of the second book of the Novum Organum. In spite of the width of his interests, especially in the domain of science, Bacon himself did not make any new discovery. His suggestions sometimes show insight, but also a certain crudity of conception which is connected with his inadequate general view of nature. The exposi tion of his method in the second book of the Novum Organum is illustrated throughout by an investigation into the form or cause of heat. The result at which he permits himself to arrive as the first vintage' of the enquiry exhibits this combination of insight and crudity. He reaches the conclusion that heat is a particular case of motion. The specific differences which distinguish it from its genus are that it is an expansive motion; that its direction is towards the circumference of the body, provided the body itself has a motion upwards; that it is a motion in the smaller parts of the body; and that this motion is a rapid motion of fine (but not the finest) particles of the body. This and other investigations of his own were abandoned without reaching a clear result. His knowledge of science was also deficient, especially in the region of the exact sciences. He looked for an increase of astronomical knowledge from Galileo's telescope, but he appears to have been ignorant of the work of Kepler; he ignored Napier's invention of logarithms and Galileo's advances in mechanical theory; and his judgment on the Copernican theory became more adverse at the very time when that theory was being confirmed by Galileo and Kepler1. These defects in his own scientific equipment were closely connected with some of the peculiarities in detail of the method he recommended. And the two things together may explain the sneer of his contemporary Harvey, that he wrote philosophy like a lord chancellor. Nor is it very difficult to understand the attitude of most subsequent men of science, who have honoured him as the originator of the experimental method but silently ignored his special precepts. His method was not the method of the laboratory. When the objects investigated can be observed only directly as they occur in nature, greater importance must be assigned to the exhaustive enumeration of facts upon which Bacon insisted. Darwin, for example, has recorded that, in 1 Compare Spedding, in Bacon's Works, 111, pp. 511, 725. |