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that whatever is true universally of any sign, must also be true of every individual which that lign can be employed to express. Admitting, therefore, that every process of reasoning may be resolved into a series of syllogisms, it follows, that this operation of the mind furnishes no proof of the existence of any thing corresponding to general terms, distinct from the individuals to which these terms are applicable.

These remarks, I am very sensible, do, by no means, exhaust the subject ; for there are various modes of reasoning, to which the fylogistic theory does not apply. But, in all of them, without exception, it will be found, on examination, that the evi. dence of our conclusions appears ima ediately from the confideration of the words in which the premis. es are expressed; without any reference to the things which they denote. The imperfect account which is given of deductive evidence, in the received systems of logic, makes it impoflible for me, in this place, to prosecute the subject any farther.

After all that I have faid on the use of language as an instrument of reasoning, I can easily foresee a variety of objections, which may occur to the doct. rine I have been endeavouring to establish. But without entering into a particular examination of these objections, I believe I may venture to affirm, that most, if not all, of them take their rise from confounding reasoning, or deduction, properly so called, with certain other intellectual processes, which it is necessary for us to employ in the investigation of truth. That it is frequently of essential importance to us, in our speculations, to withdraw our attention from words, and to direct it to the things they denote, I am very ready to acknowl. edge. All that I assert isthat, in so far as our speculations consist of that process of the mind which is properly called reasoning, they may be carried on

by words alone ; or, which comes to the same thing, that every process of reasoning is perfectly analogous to an algebraical operation. What I mean by " the other intellectual processes diftinct from rea“soning, which it is necessary for us sometimes to "employ in the investigation of truth,” will, I hope, appear clearly from the following remarks.

În algebraical investigations, it is well known, that the practical application of a general expreffion, is frequently limited by the conditions which the hypothesis involves; and that, in consequence of a want of attention to this circumftance, some math. ematicians of the first eminence have been led to a. dopt the most paradoxical and absurd conclusions. Without this cautious exercise of the judgment, in the interpretation of the algebraical language, no dexterity in the use of the calculus will be sufficient to preserve us from error. Even in algebra, therefore, there is an application of the intellectual

pow. ers perfectly diftinct from any process of reasoning; and which is absolutely necessary for conducting us to the truth.

In geometry, we are not liable to adopt the same paradoxical conclusions, as in algebra ; because the diagrams to which our attention is directed, serve as à continual check on our reasoning powers. These diagrams exhibit to our very senses, a variety of relations among the quantities under consideration, which the language of algebra is too general to express ; in consequence of which, we are not conscious of any effort of the judgment distinct from a process of reasoning. As every geometrical investigation, however, may be expreffed algebraically, it is manifeft, that, in geometry, as well as in algebra, there is an exercise of the intellectual powers, distinct from the logical process ; although, in the former science, it is rendered fo easy, by the use of diagrams, as to escape our attention.

The same source of error and of absurdity, which exists in algebra, is to be found, in a much greater degree, in the other branches of knowledge. Abftracting entirely from the ambiguity of language ; and supposing also nur reasonings to be logically accurate, it would still be necessary for us, from time to time, in all our speculations, to lay aside the use of words, and to have recourse to particular examples, or illustrations, in order to correct and to limit our general conclusions.To a want of attention to this circumstance, a number of the speculative absurdi. ties which are current in the world, might, I am persuaded, be easily traced.

Besides, however, this source of error, which is in fome degree comnion to all the sciences, there is a great variety of others, from which mathematics are entirely exempted : and which perpetually tend to lead us aftray in our philosophical inquiries. Of these, the most important is, that ambiguity in the signification of words, which renders it fo 'difficult to avoid employing the same expressions in different senses, in the course of the fame process of reasoning. This source of mistake, indeed, is apt, in a much greater degree, to affect our conclusions in metaphysics, morals, and politics, than in the different branches of natural philosophy ; but, if we except mathematics, there is no science whatever, in which it has not a very sensible influence. In algebra, we may proceed with perfect safety through the longest investigations, without carrying our attention beyond the signs, till we arrive at the last result. But in the other sciences, excepting in those cases in which we have fixed the meaning of all our terms by accurate definitions, and have rendered the use of these terms perfectly familiar to us by very long habit, it is but seldom that we can proceed in this manner without danger of error. In many cases, it is necessary for us to keep up, during the whole of our investigations, a scrupulous and conftant attention to the signification of our expressions ; and, in most cases, this caution in the use of words, is a much more difficult effort of the mind, than the logical process. But still this furnishes no exception to the general doctrine already delivered ; for the attention we find it neceffary to give to the import of our words, arises only from the accidental circumstance of their ambiguity, and has no effential connection with that process of the mind, which is properly called reasoning; and which consists in the inference of a conclusion from premises. In all the sciences, this process of the mind is perfectly analogous to an algebraical operation ; or, in other words, (when the meaning of our expressions is orce fixed by definitions,) it may be carried on intirely by the use of signs, without attending, during the time of the process, to the things fignified.

The conclufion to which the foregoirig observations lead, appears to me to be decisive of the quel tion, with respect to the objects of our thoughts when we employ general terms; for if it be granted, that words, even when einployed without any reference to their particular signification, form an instrument of thought sufficient for all the purposes of reasoning; the only shadow of an argument in proof of the common doctrine on the subject, (I mean that which is founded on the impossibility of explaining this process of the mind on any other hypothesis,) falls to the ground. Nothing less, surely, than a conviction of this impossibility, could have fo long reconciled philosophers to an hypothesis unsupported by any direct evidence; and acknowledged even by its warmest defenders, to involve much dif. ficulty and mystery.

It does not fall within my plan, to enter, in this part of my work, into a particular confideration of the practical consequences which follow from the

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foregoing doctrine. I cannot, however, help remarking the importance of cultivating, on the one hand, a talent for ready and various illustration; and, on the other, a habit of reasoning by means of general terms. The former talent is necessary, not only for correcting and limiting our general conclufions, but for enabling us to apply our knowledge, when occasion requires, to its real practical use. The latter ferves the double purpose, of preventing our attention from being distracted during the course of our reasonings, by ideas which are foreign to the point in question ; and of diverting the attention from thofe conceptions of particular objects and particular events which might disturb the judgment, by the ideas and feelings, which are apt to be associated with them, in consequence of our own casual experience.

This laft observation points out to us, also, one principal foundation of the art of the orator. As his object is not so much to inform and to fatisfy the understandings of his hearers, as to force their immediate affent; it is frequently of use to him to clothe his reasonings in that specific and figurative language, which may either awaken in their minds associations favorable to his purpofe, or may divert their attention from a logical examination of his ar. gument. A process of reasoning fo exprefled, aftords at once an exercise to the judgment, to the imagination, and to the passions; and is apt, even when loofe and inconsequential, to impose on the best understandings.

It appears farther, from the remarks which have been made, that the perfection of philosophical lan. guage, considered either as an instrument of thought, or as a medium of communication with others, con. fists in the use of expressions, which from their generality, have no tendency to awaken the powers of conception and imagination; or, in other words, it

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