INTRODUCTION.

THE inadequacy of the words of ordinary language for the purposes of Philosophy, is an ancient and frequent complaint; of which the justness will be felt by all who consider the state to which some of the most important arts would be reduced, if the coarse tools of the common labourer were the only instruments to be employed in the most delicate operations of manual expertness. The watchmaker, the optician, and the surgeon, are provided with instruments which are fitted, by careful ingenuity, to second their skill; the philosopher alone is doomed to use the rudest tools for the most refined purposes. He must reason in words of which the looseness and vagueness are suitable, and even agreeable, in the usual intercourse of life, but which are almost as remote from the extreme exactness and precision required, not only in the conveyance, but in the search of truth, as the hammer and the axe would be unfit for the finest exertions of skilful handiwork: for it is not to be forgotten, that he must himself think in these gross words as unavoidably as he uses them in speaking to others. He is in this respect in a worse condition than an astronomer who looked at the heavens only with the naked eye, whose limited and partial observation, however it might lead to error, might not directly, and would not necessarily, deceive. He might be more justly compared to an arithmetician compelled to employ numerals not only cumbrous, but used so irregularly to denote different quantities, that they not only often deceive others, but himself.

The natural philosopher and mathematician have in some degree the privilege of framing their own terms of art; though that liberty is daily narrowed by the happy diffusion of these great branches of

knowledge, which daily mixes their language with the general vocabulary of educated men. The cultivator of mental and moral philosophy can seldom do more than mend the faults of his words by definition; — a necessary, but very inadequate expedient, and one in a great measure defeated in practice by the unavoidably more frequent recurrence of the terms in their vague, than in their definite acceptation. The mind, to which such definition is faintly, and but occasionally, present, naturally suffers, in the ordinary state of attention, the scientific meaning to disappear from remembrance, and insensibly ascribes to the word a great part, if not the whole, of that popular sense which is so very much more familiar even to the most veteran speculator. The obstacles which stood in the way of Lucretius and Cicero, when they began to translate the subtile philosophy of Greece into their narrow and barren tongue, are always felt by the philosopher when he struggles to express, with the necessary discrimination, his abstruse reasonings in words which, though those of his own language, he must take from the mouths of those to whom his distinctions would be without meaning.

The moral philosopher is in this respect subject to peculiar difficulties. His statements and reasonings often call for nicer discriminations of language than those which are necessary in describing or discussing the purely intellectual part of human nature; but his freedom in the choice of words is more circumscribed. As he treats of matters on which all men are disposed to form a judgment, he can as rarely hazard glaring innovations in diction, at least in an adult and mature language like ours, as the orator or the poet. If he deviates from common use, he must atone for his deviation by hiding it, and can only give a new sense to an old word by so skilful a position of it as to render the new meaning so quickly understood that its novelty is scarcely perceived. Add to this, that in those most difficult inquiries for which the utmost coolness is not more than suf

ficient, he is often forced to use terms commonly connected with warm feeling, with high praise, with severe reproach; - which excite the passions of his readers when he most needs their calm attention and the undisturbed exercise of their impartial judgment. There is scarcely a neutral term left in Ethics; so quickly are such expressions enlisted on the side of Praise or Blame, by the address of contending passions. A true philosopher must not even desire that men should less love Virtue, or hate Vice, in order to fit them for a more unprejudiced judgment on his speculations.

There are, perhaps, not many occasions where the penury and laxity of language are more felt than in entering on the history of sciences where the first measure must be to mark out the boundary of the whole subject with some distinctness. But no exactness in these important operations can be approached without a new division of human knowledge, adapted to the present stage of its progress, and a reformation of all those barbarous, pedantic, unmeaning, and (what is worse) wrongmeaning names which continue to be applied to the greater part of its branches. Instances are needless where nearly all the appellations are faulty. The term "Metaphysics" affords a specimen of all the faults which the name of a science can combine. To those who know only their own language, it must, at their entrance on the study, convey no meaning: it points their attention to nothing. If they examine the language in which its parts are significant, they will be misled into the pernicious error of believing that it seeks something more than the interpretation of nature. It is only by examining the history of ancient philosophy that the probable origin of this name will be found, in its application, as the running title of several essays of Aristotle, placed in a collection of the manuscripts of that great philosopher, after his treatise on Physics. It has the greater fault of an unsteady and fluctuating signification ; — denoting

one class of objects in the seventeenth century, and another in the eighteenth; - even in the nineteenth not quite of the same import in the mouth of a German, as in that of a French or English philosopher; to say nothing of the farther objection that it continues to be a badge of undue pretension among some of the followers of the science, while it has become a name of reproach and derision among those who altogether decry it. The modern name of the very modern science called "Political Economy," though deliberately bestowed on it by its most eminent teachers, is perhaps a still more notable sample of the like faults. It might lead the ignorant to confine it to retrenchment in national expenditure; and a consideration of its etymology alone would lead us into the more mischievous error of believing it to teach, that national wealth is best promoted by the contrivance and interference of lawgivers, in opposition to its surest doctrine, and the one which it most justly boasts of having discovered and enforced.

It is easy to conceive an exhaustive analysis of human knowledge, and a consequent division of it into parts corresponding to all the classes of objects to which it relates:-a representation of that vast edifice, containing a picture of what is finished, a sketch of what is building, and even a conjectural outline of what, though required by completeness and convenience, as well as symmetry, is yet altogether untouched. A system of names might also be imagined derived from a few roots, indicating the objects. of each part, and showing the relation of the parts to each other. An order and a language somewhat resembling those by which the objects of the sciences of Botany and Chemistry have, in the eighteenth century, been arranged and denoted, are doubtless capable of application to the sciences generally, when considered as parts of the system of knowledge. The attempts, however, which have hitherto been made to accomplish that analytical division of knowledge which must necessarily precede a new nomenclature