conclusive.' In this position the question remains to the present day; it may be that the effect was too slight to be detected, or it may be that the arrangments adopted were not suited to develope the particular relation which exists, just as Oersted could not detect electro-magnetism, so long as his wire was perpendicular to the plane of motion of his needle. But these are not matters which

concern us further here. We have only to notice the profound conviction in the unity of natural laws, the active powers of inference and imagination, the unbounded licence of theorizing, combined above all with the utmost diligence in experimental verification which this remarkable research manifests.

Reservation of Judgment.

There is yet another characteristic needed in the philosophic mind; it is that of suspending judgment when the data are insufficient. Many people will express a confident opinion on almost any question which is put before them, but they thereby manifest not strength, but weakness and narrowness of mind. To see all sides of a complicated subject, and to weigh all the different facts and probabilities correctly, may require no ordinary powers of comprehension. Hence it is most frequently the philosophic mind which is in doubt, and the ignorant mind which is ready with a positive decision. Faraday has himself said, in a very interesting lecturei, 'Occasionally and frequently the exercise of the judgment ought to end in absolute reservation. It may be very distasteful, and great fatigue, to suspend a conclusion; but as we are not infallible, so we ought to be cautious; we shall eventually find our advantage, for the man who

i Printed in Modern Culture,' edited by Youmans, p. 219.

.ces; have no favourite hypothesis; be of no and in doctrine have no master. He should not pecter of persons, but of things. Truth should be ary object. If to these qualities be added inhe may indeed hope to walk within the veil of ple of nature.'

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now that Mr. Gladstone must die, because he is like en? May we not argue that because some men die

he must? Is it requisite to ascend by induction general proposition all men must die,' and then 1 by deduction from that general proposition to the Mr. Gladstone? My answer will be undoubtedly t is necessary to ascend to general propositions. indamental principle of the substitution of similars us no warrant in affirming of Mr. Gladstone what now of other men, simply because we cannot be that Mr. Gladstone is exactly similar to other men.

his death we cannot be perfectly sure that he sses precisely all the attributes of other men; it is uestion of probability, and I have endeavoured to ain the mode in which the theory of probability is lied to calculate the probability that from a series imilar events we may infer the recurrence of like nts under identical circumstances. There is then no h process as that of inferring from particulars to parulars. A careful analysis of the conditions under which ch an inference appears to be made, shows that the ocess is really a general one, and that what is inferred a particular case might be inferred of all similar cases. all reasoning is essentially general, and all science implies. eneralization. In the very birth-time of philosophy this vas held to be so: Nulla scientia est de individiis, sed le solis universalibus,' was the doctrine of Plato, delivered by Porphyry. And Aristotlea held a like opinionΟὐδεμία δὲ τέχνη σκοπεῖ τὸ καθ ̓ ἕκαστον . . . τὸ δὲ καθ ̓ ἕκαστον tò ἄπειρον, καὶ οὐκ ἐπιστητόν. Νo art treats of particular cases; for particulars are infinite and cannot be known.' No one who holds the doctrine that reasoning may be from particulars to particulars, can be supposed to have

a Aristotle's 'Rhetoric,' Liber I. 2. 11.