admit of an answer, Valerius Terminus appears to suggest it. Bacon connected the doctrine of Forms with practical operations, because this doctrine, so to speak, represented to him his original notion of the freeing of a direction, which, as the phrase itself implies, had altogether a practical significance.

1

Even in the Novum Organum the definition of the Form is made to correspond with the præceptum operandi, or practical direction. The latter is to be "certum, liberum, et disponens sive in ordine ad actionem." Now a direction to produce the Form as a means of producing the given nature is certain, because the presence of the Form necessarily determines that of the nature. It is free, because it requires only that to be done which is necessary, since the nature can never be present unless its Form is so too. Thus far the agree ment between the practical and the scientific view is satisfactory. But to the third property which the practical direction is to possess, namely its being in ordine ad actionem, or such as to facilitate the production of the proposed result, corresponds the condition that the Form is to be "the limitation of a more general nature;" that is to say, the Form presents itself as a limitation of something more general than the given nature, and as determining, not merely logically but also causatively, the existence of the latter. At this point the divergence between the practical and the scientific view becomes manifest; practical operations do not, generally speaking, present to us anything analogous to the limitation here spoken of, and there is no reason to suppose that it is easier to see how this limi

1 Nov. Org. ii. 4., which is the best comment on the dictum, Knowledge is power.

tation is to be introduced than to see how the original problem, the έ åpxîs πpokeíμevov, may be solved. But this divergence seems to show that the two views are in their origin heterogeneous; that the one contains the fundamental idea of Bacon's method, while the other represents the historical element of his philosophy. We shall however hereafter have occasion to suggest considerations which may seem to modify this conclusion.

(12.) In a survey of Bacon's method it is not necessary to say much of the doctrine of prerogative instances, though it occupies the greater part of the second book of the Novum Organum. It belongs to the unfinished part of that work; at least it is probable that its practical utility would have been explained when Bacon came to speak of the Adminicula Inductionis.

Twenty-seven kinds of instances are enumerated, which are said to excel ordinary instances either in their practical or their theoretical usefulness. To the word instance Bacon gives a wide range of signification. It corresponds more nearly to observation than to any other which is used in modern scientific language.

Of some classes of these instances collections are to be made for their own sake, and independently of any investigation into particular natures. Such, for instance, are the instantiæ conformes; Bacon's examples of which are mostly taken from comparative anatomy. One of them is the analogy between the fins of fishes, the feet of quadrupeds, and the feet and wings of birds; another, the analogy of the beak of birds and the teeth of other animals, &c.1

1 Nov. Org. ii. 27. It does not seem that Bacon added much to what he found in Aristotle on the subject of these analogies.

The other classes of prerogative instances have especial reference to particular investigation, and are to be collected when individual tables of comparence are formed.

It would seem from this that the theory of prerogative instances is intended to guide us in the formation. of these tables. But it is difficult to see how the circumstances which give any instance its prerogative could have been appreciated à priori. An instantia crucis, to take the most celebrated of all, has its distinguishing character only in so far as it is viewed with reference to two contending hypotheses. In forming at the outset of an inquiry the appropriate tables, nothing would have led the interpreter to perceive its peculiar value.

This theory, whatever may be its practical utility, may supply us with new illustrations of the importance in Bacon's method of the process of exclusions.

At the head of the list-and placed there, we may presume, from the importance of the end which they promote stand the instantiæ solitariæ, whose prerogative it is to accelerate the Exclusiva.2 These are instances which exhibit the given nature in subjects which have nothing in common, except that nature itself, with the other subjects which present it to us. Thus the colours shown by the prism or by crystals are a solitary instance of colour, because they have nothing in common with the fixed colours of flowers, gems, &c. Whatever therefore is not independent of the particular constitution of these bodies must be exIcluded from the form of colour.

Next to the instantiæ solitariæ are placed the instan2 Nov. Org. ii. 22.

1 Nov. Org. ii. 36.

tiæ migrantes, which show the given nature in the act of appearing or of disappearing; as when glass, being pounded, becomes white. Of these it is said that they not only accelerate and strengthen the Exclusiva, but also confine within narrow limits the Affirmative, or Form itself, by showing that it is something which is given or taken away by the observed change. A little farther on Bacon notices the danger in these cases of confounding the efficient cause with the Form, and concludes by saying "But this is easily remedied by a legitimately performed Exclusiva."

Other remarks to the same effect might be made with reference to other classes of instances; but these are probably sufficient.

I shall now endeavour to give an account of Bacon's views on some questions of philosophy, which are not immediately connected with the reforms he proposed to introduce.

(13.) It has sometimes, I believe, been supposed that Bacon had adopted the atomic theory of Democritus. This however is by no means true; but certainly he often speaks much more favourably of the systems of the earlier physicists, and especially of that of Democritus, than of the philosophy of Plato and Aristotle. In doing this he may, perhaps, have been more or less influenced by a wish to find in antiquity something with which the doctrines he condemned might be contrasted. But setting this aside, it is certain that these systems were more akin to his own views than the doctrine of the schools of which Socrates may be called the founder. The problems which they proposed were essentially physical, -given certain material first prin

ciples, to determine the origin and causes of all phenomena. They were concerned, for the most part, with that which is accessible to the senses, or which would be so if the senses were sufficiently acute. In this they altogether agree with Bacon, who, though he often speaks of the errors and shortcomings of the senses, yet had never been led to consider the question which stands at the entrance of metaphysical philosophy, namely whether the subjective character of sensation does not necessarily lead to scepticism, if no higher grounds of truth can be discovered. The scepticism of Protagoras, and Plato's refutation of it, seemed to him to be both but idle subtleties. Plato, Aristotle, and their followers, were in his opinion but a better kind of sophists. What Dionysius said to Plato, that his discourse was but dotage, might fitly be applied to them all.1

It cannot be denied, that to Bacon all sound philosophy seemed to be included in what we now call the natural sciences; and with this view he was naturally led to prefer the atomic doctrine of Democritus to any metaphysical speculation. Every atomic theory is an attempt to explain some of the phenomena of matter by means of others; to explain secondary qualities by means of the primary. And this was what. Bacon himself proposed to do in investigating the Forms of simple natures. Nevertheless he did not adopt the peculiar opinions of Democritus and his followers. In the Novum Organum he rejects altogether the notion of a vacuum and that of the unchangeableness of matter.2 His theory of the intimate constitution of bodies does

1 Redargut. Phil. et Nov. Org. i. 71.

2 Nov. Org. ii. 8. Compare Cogit. De Nat. Rerum.