To have reached, in the study of observed phenomena, the point of perception indicated in this motto, and to feel the full force of the remark, is to have imbibed the spirit of science—-whose traits are dear distinctions, accurate classification, and strict reference to primitive data. The bases of all science are methodical facts. The first step to the perfection and enlargement of a science is the resolution of its propositions into axioms, and into propositions which are to be proved. Dr. Reid observes—'This has been done in mathematics from the beginning, and has tended greatly to the emolument of that science. It has lately been done in natural philosophy, and by this means that science has advanced more in 160 years than it had done before in 2,000. Every science is in an unformed state until its first principles are ascertained; after this it advances regularly, and secures the ground it has gained.'

Classification is one of the first steps to Science. The maxim in government, divide and conquer, retains, when applied to science, all its wisdom without its machiavelialism. The young grammarian reduces the mass of words, that so threaten to confound his powers, to a few natural classes, and he conquers them separately with ease.

'The single power by which we discover resemblance or relation in general, is a sufficient aid to us in the perplexity and confusion of our first attempts at arrangement. It begins by converting thousands, and more than thousands, into one; and, reducing in the same manner the numbers tiros formed, it arrives at last at the few distinctive characters of those great comprehensive tribes, on which it ceases to operate, 'because there is nothing left to oppress the memory or the understanding.'*

Merell has spoken more comprehensively on this subject—'That human knowledge dees not consist in the bare collection and enumeration of facts; this alone would be of little service were we net to attempt the classification of them, and to educe from such classification general laws and principles. The knowledge, which consists in individual truths, could never be either extensive ear definite—for the multiplicity of objects which then must crowd in upon the mind only tends to confound and perplex it, while the memory, overburdened with particulars, is not able to retain a hundredth part of the materials which are collected. To prevent this, the power el generalisation comes to our aid, by which the individual facts are so classified under their proper conceptions, that they may at the same time be more easily retained, and their several relations to all other branches of knowledge accurately defined. The colligation and classification of facts, then, we may regard as the two first steps, which are to be taken in the attainment of truth.'*

Aristotle, says Morell, classified the matter, Kant the forms. Aristotle was the first man who undertook the gigantic task of reducing the multiplicity of all the objects of human knowledge to a few general heads—-1. Substance. 2. Quality. 3. Quantity. 4. Relation. Action. 6. Passion. 7. Place. 8. Time. 9. Posture. 10. Habit. Aristotle's philosophy was objective, Kant's subjective. Kant's categories were twelve. 1. Unity. 2. Plurality. 3. Totality. 4. Affirmation. Negation. 6. limitation. 7. Substance. 8. Casualty. 9. Reciprocity. 10. Possibility. 11. Actuality. 12. Necessity.

'It is a fundamental principle in logic, that the power of framing classes is unlimited as long as there is any (even the smallest) difference to found a distinction upon.**

What Geoffroy Saint Hilaire has said of natural history is applicable to all science:—'The first problem to be solved by him who wishes to penetrate deeply into this; study, consists evidently in the formation of clear and precise distinctions between the various brings. This is the most elementary problem, in so-far as it precedes all the others; but it is in reality, in most cases, complicated and full of difficulties. Its accurate solution requires—first, Observation, which makes known the facts; next, Description, which fixes them permanently; then Characterisation, which selects and displays prominently the most important of them—and lastly, Classification, which arranges them in systematic order.'***

Of the value of classification, Lamartine has given a fine illustration:——'Montesquieu had sounded the institutions and analysed the laws of all people. By classing governments he had compared them, by comparing them he passed judgment on them; and this judgment brought out, in its bold relief and contrast, on every page, right and force, privilege and equality, tyranny and liberty.'****

Familiarity with the characteristics of science imparts considerable power for the detection of fallacy. A logician is imperfect without scientific tastes and habits. The man of science has all his knowledge systematised and arranged. What other people have in confusion, he has in order. The elements of knowledge are, more or less, as has been observed, known to all men—but in their perfect, communicable, and usable state, they are-known only to the educated and scientific man. What training is to the soldier, science is to the thinker. It enables him to control all his resources and employ his natural powers to the best advantage. It is this which constitutes the superiority of the educated over the ignorant. Astronomy, navigation, architecture, geometry, political economy, morals, all rest, or should rest, and do rest, if they have-attained to the perfection of science, on primary facts and first principles. Every step can be measured by an axiom—every result can be traced to a first principle.* To detect error, then, in any province of investigation, or any domain of argument, the logician first looks to the primary principles on which it is based, and thus tests the legitimacy of its conclusions.

As respects those who deal in things professedly above reason, It was well said by an anonymous writer of the old school of sturdy thinkers,—'Of such men as these I usually demand, whether their own assent to things they would have us believe, be grounded upon some rational argument. If they say 'tis not, they are fools to believe it themselves; and I should add to the number of fools, if, after this acknowledgment, I should believe them: but if they say it is, I desire them to produce their argument; for since 'tis framed by a human understanding, the force of it may also be comprehended and judged of by a human understanding: and tis to no purpose to say that the subject surpasses human reason: for if it do so indeed, it will surpass theirs as well as mine, and so leave us both upon even terms. And let the thing assented to be what it will, the assent itself must be founded upon a sufficient reason, and consequently upon one that is intelligible to the human intellect that is wrought on by it.'**

"What is it?—" "'Tis impossible the same thing should be, and not be at the same time," are maxims of such universal usefulness, that without them we could neither judge, discourse, nor act. These principles may not always make their appearance in formal propositions, but still they guide all our thoughts in the same manner as when a musician plays a careless voluntary upon a harpsichord—he is guided by rules of music he long since became familiar with, though now scarcely sensible of them.

'A butcher loses his knife, and looks all about for it, and remarks as the motive of his search, "I am sure it must be somewhere or other." By which rude saying it is evident he is guided by the axiom last mentioned. Had he not the knowledge of this axiom beforehand, did he think it possible that his knife could be no where or in no place he would never take pains to look for it. We may observe many such axioms as this guiding the actions of the vulgar, and it is no unworthy speculation to observe their behaviour and words, which proceed from uncorrupted nature, and retrieve the axioms from which their conduct proceeds.'*

The outlines of the science of morality are thus comprehensively sketched by Sir James Mackintosh: the origin, value, and application of first principles are indicated with his usual felicity. 'The usages and laws of nations, the events of history, the opinions of philosophers, the sentiments of orators and poets, as well as the observations of common life, are in truth, the materials out of which the science of morality to formed; and those who neglect them are justly chargeable with a vain attempt to philosophise without regard to fact and experienee—the sole foundation of all true philosophy.

The natural order undoubtedly dictates that we should first search for the original principles of the science in human nature; then apply them to the regulation of the conduct of individuals, and lastly employ them for the decision of those difficult and complicated questions that arise with respect to the intercourse of nations.'

To search for ultimate principles is to discover at a glance the whole bearings of a great question. Through what clouds of politics had the historian of Rome penetrated when he announced that the principles of a free constitution are irrecoverably lost when the legislative power is nominated by the executive.

This habit—it cannot be too often insisted on aids not only the acquisition of knowledge, but also its retention. Around these first principles, as around a standard, the thoughts naturally associate. Touch but a remote chord of any question, and it will vibrate to the central principle to which it has once been well attached. Every relative impression owns a kindred connection, and the moment one is attacked, it, like a faithful sentinel, arouses a whole troop, which, marshalled and disciplined, bear down and challenge the enemy.'*

What Rogers has so exquisitely sung of the associations of childhood, is true of the associations of science.