tigation, at least in physical sciences, was first indicated by Bacon.

But this opinion, though general, has not been universal. There have not been wanting, even in modern times, those who have contended, that the Baconian system of induction, as generally understood, is erroneous; that the first principles of philosophy cannot be deduced from the facts of experience which they are intended to explain, but must be developed by the pure light of reason, undistracted by sensible impressions, and operating on the objects of its internal consciousness alone; that then, from these first principles, thus ascertained, as from a geometrical axiom, are to be deduced in a descending series, those secondary and tertiary laws, which are of more partial operation, and by which the phenomena that present themselves to the senses are directly explained. With every respect for those by whom these doctrines have been advocated, I cannot but consider them as so opposed to all sound philosophy, so dangerous to the future progress of discovery, and moreover so contrary to the example of John Hunter which we are assembled this day to commemorate, that I feel I should ill fulfil the intention of those who founded this oration, were I to pass them over in silence. When the foundations of all modern science are endangered, it becomes necessary to survey them with the view of ascertaining their solidity. Nor is there any better protection

2

against the intrusion of error, than an accurate comparison between it and truth.

It will be observed, then, that the two systems of philosophy which have been described, differ in the basis on which they rest, in the course which they hold, and in the proofs to which they appeal : nor can the difference be better stated than in the words of Lord Bacon himself. As to the original basis, he describes the one as an anticipatio mentis, the other as an interpretatio nature; that is, the one as resting on human notions rashly and prematurely formed, the other as resting on the facts of nature carefully collected and interpreted by cautious reasoning. "Omnes ante nos,” says he, "qui ad artes inveniendas se applicuerunt, conjectis paulisper in res, et exempla, et experientiam oculis, statim, quasi inventio nil aliud esset quàm quædam excogitatio, spiritus proprios, ut sibi oracula exhiberent, quodammodo invocârunt. Nos verò, inter res cautè et perpetuò versantes, intellectum longiùs a rebus non abstrahimus, quàm ut rerum imagines, et radii (ut in sensu fit) coire possint."*

As to the course which they hold in their progressive development, he tells us, that the one having established by hasty anticipation certain wide and comprehensive principles, deduces from these by logical inference the axiomata media, the less general laws which are applicable to the

* Bacon, Nov. Org. Præf.

practice of life that the other ascertains first by careful observation the axiomata media, and then ascends by gradual and regular induction to the more general laws of the universe. The former method, though easy and compendious, is attended with this grievous evil, that an error in the original principle affects all the conclusions which are deduced from it: the latter, though longer and more laborious, corrects in its progress any error which may have been admitted, and thus establishes its conclusions on a certain and irrefragable basis. His words are remarkable: "Ordo demonstrandi planè invertitur. Adhuc enim res ità geri consuevit, ut a sensu et particularibus primo loco ad maximè generalia advoletur, tanquam ad polos fixos circa quos disputationes versantur; ab illis cætera per media deriventur, viá certé compendiaria, sed præcipiti; et ad naturam imperviá, ad disputationes verò proclivi et accommodatá. At secundùm nos, axiomata continenter et gradatim incitantur, ut non nisi postremo loco ad generalissima veniatur."*

Then as to the proofs to which they severally appeal. The one assumes that the notions of the human mind are necessarily correct, and appeals therefore to each man's consciousness for the justification of its doctrines: the other rejects all confidence in the notions of the intellect, unless their truth is demonstrated at every step by observation *Bacon, Nov. Org. Dist. Op.

and experiment; by their accordance with the evidence of the senses, and the results of expe

"ad

rience. "Quod attinet," says Lord Bacon, notiones primas intellectús, nihil est eorum quæ intellectus, sibi permissus, congessit, quin nobis pro suspecto sit, nec ullo modo ratum, nisi novo judicio se stiterit, et secundùm illud pronuntiatum fuerit."*

I have been the more particular in stating, from Lord Bacon himself, these essential characteristics of the two systems, because it is to be feared, that, while we have been engaged in rearing the superstructure of science, its foundations, as laid by that great man, have been in some degree forgotten. How otherwise should it be, that the errors he refuted should be reproduced as newly-discovered truths? Nay, that the authority of Lord Bacon himself should be claimed for a system, evidently identical with that which it was the great labour of his life to overthrow.

Here then are two ways, by which we may seek to unfold the laws which the Creator has imposed on his works. The one is to read them in the works themselves; the other to discover them by solitary contemplation. The one investigates by the evidence of the senses the facts of the world around, and endeavours to discover, by reason and varied research, that order which the Creator has been pleased to establish in it. The other puts man, if the expression may be allowed, in the place of

*Bacon, Nov. Org. Dist. Op.

the Creator, and determines, à priori, what laws must be ordained by Infinite Wisdom for the regulation of a world which Infinite Power was about to create. Can anything equal the presumption of such an attempt? That a mortal man,-his knowledge limited to the little corner of the little planet he inhabits; his life but a span; half of that span passed before his intellect has attained its maturity, -should imagine himself able to construct the wonderful world which surrounds him, with its infinite variety, its regular gradations, its perpetual flux and reparation; including within it innumerable millions of distinct volitions, each capable of independent action, each influenced by its own individual motives, yet all cooperating to fulfil the designs of one unerring Prescience; that, I say, man should imagine he could construct such a world, is a presumption which almost exceeds the possibility of belief, and which would doubtless be disowned by those who nevertheless avow the doctrine of which it is the legitimate inference. For is it not so? He who, never having examined a watch, yet devises its construction, is equal to the original inventor. He who could sketch the plan of the universe, not from the contemplation of its form and operations, but from the suggestions of his own intellect, could not but approach, if the expression may be permitted, to that Infinite Wisdom, "In whose thought the world Fair as it is, existed ere it was."*

* Cowper.