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.'****