Imatges de pÓgina
PDF
EPUB

be requifite to take notice of every circumstance that circumstance that may tend to throw light and evidence upon a doubtful fpeculation.

In fuch an enumeration of arguments, it is not adviseable to place a flight probability in the same rank with arguments which are much stronger and more conclufive. Rather, fince there are so many ways in which, with a little address, it may be introduced to more advantage, in an indirect manner, let it be hinted at in fome other place. Very often an argument, disguised in the form of an epithet, a metaphor, a comparison or illustration, &c. is more pleafing, looks more like a redundancy of argument, and in every respect hath a better effect, than if it were placed in an equal rank with arguments of more weight. Indeed, in such a fituation, it might be construed to look like a diffidence of our cause, and a folicitude to make the most of every argument favourable to it.

If the arguments be nearly equal in weight, no order drawn from their comparative ftrength is to be preferred to that natural order which is fuggested by the subjects from which they are derived.

After the demonstration of the propofition, the geometrician, if there be occafion, makes mifcellaneous remarks, ferving to throw light upon the fubject, under the name of Jfcholia. And fuch like observations, particularly fuch as illuftrate the nature and force of the evidence, or point out fimilar proceffes in other fubjects, throw an agreeable variety into a compofition, and tend, in an indirect manner, to ftrengthen the preceding arguments.

Laftly, in the form of Corollaries, the geometrican deduces from his propofition, now fully proved, other truths which flow from it, if the dependance be fo ftrict that it would have appeared trifling to make them formal propofitions.

[ocr errors]

In like manner, when there is no danger of too greatly multiplying the objects of attention, it may have a good effect to fhow the extensive and happy influence of the principle we have been maintaining, by tracing its beneficial confequences, and showing the connexion it hath with other acknowledged truths; particularly when those confequences, and those connexions with other truths, are of fuch a nature, that they could not conveniently be introduced into the body of the discourse, by way of arguments in favour of the propofition we maintain.

Having explained pretty much at large how all the proper parts of an argumentative difcourfe, calculated to inform the understanding, should be disposed, in order to produce their proper effect, I shall fubjoin the following brief fummary of the procefs.

The meaning of the terms of the propofition should be accurately fixed, principles made use of in the demonstration distinctly noted, and, if there be occafion, proved; the question stated in the most intelligible manner, with a circumftantial relation of every fact that may contribute to set it in the clearest point of light, and the subject divided into the diftin&t parts of which it confifts. The order of nature must chiefly be confulted in arranging the arguments brought to fupport each of them, and flight probabilities fhould be introduced in an indirect manner. Obfervations relating to the nature of the proof that is made use of, with the connexion and mutual influence of the feveral arguments, and other miscellaneous remarks that may naturally occur, come next; and the whole difcourfe clofes with a view of the extent of the doctrine, in all the valuable inferences and ufes that may be drawn from it.

The

The principal faults in the several parts of this kind of difpofition, may be seen in the following brief enumeration of them.

As it is highly requifite to define ftrictly every term in the propofition, when the meaning of it is in danger of being mistaken; so it is affected and trifling to define those that, it is morally certain, will not be misunderstood.

We cannot be too cautious what principles we take for granted in order to argue from. These axioms are the foundation of our whole fuperftructure.. We ought, therefore, very rarely, and not without the most urgent neceffity, to have recourse to argumenta ad hominem; being sensible that though such arguments may lead fome particular perfons into a right way of thinking, the connexion between truth and falsehood cannot be natural, and promises but ill to be lafting; and that whenever such persons begin to be aware that the principles from which you argued with them were falfe, they of course give up the fentiments. which were deduced from them.

4

Distribution is the most faulty when the parts are not of the fame nature and order, and not fufficiently diftinct; and by no means should any one of them comprehend any of the rest. Rather subdivide the principal heads of a difcourfe into subordi

[ocr errors]
[ocr errors]

nate ones.

It is a capital fault in the difpofition of an argumentative difcourfe, to divide the fubject in fuch a manner, as that the writer fhall have occafion for the fame amplification in different parts of it. This is the confequence of making the heads of discourse too much fimilar to one another. It is more ad-viseable to make fewer heads, and those more distinct.

In a difcourfe, in which a great variety of arguments are used, it hath a good effect both to give a general view of them before they be separately enlarged upon, and to give a distinct recapitulation of them after the amplification; as it makes the evidence more intelligible, and unites the force of all the arguments.

Introductions to difcourfes admit of great variety, according to the nature of the fubject, the circumstances of the speaker, and of the persons he addreffes. Since the end that is propofed by every thing that is faid, previous to our entering upon any subject, is to procure us a more favourable hearing, and thereby prepare the way for the arguments that we intend to advance, we may, with advantage, introduce a subject by a variety of general remarks concerning it, particularly fuch as tend to show the use and importance of it; or by fhewing the propriety of treating it at that particular time, in that particular place, in that particular manner, &c. It may also be very expedient to introduce an obnoxious fubject, by removing preconceived prejudices, and anfwering popular objections.

Introductions may likewise be fuggefted by a variety of temporary circumftances, impoffible to be defcribed beforehand, but which naturally occur to a speaker, or writer, in the circumstances proper for them. See Cicero's introductions to his philofophical and rhetorical difcourfes, and alfo thofe to his orations. In the latter there is generally the greatest propriety; but the former have no peculiar relation to the pieces to which they are prefixed. Indeed, he acknowledges that they were compofed before he knew what use he should make of them. The introductions to the two histories of Salluft are juftly to be found fault with on the fame account.

LECTURE

LECTURE IX.

Of the ANALYTIC METHOD. Of Locke's Effay on the Human Understanding, and Hutchefon's Moral Philofophy.

T

HE regular and unmixed fynthefis is beft adapted (as was observed above) to fubjects, the theories of which are ascertained, or systems for the use of learners; who, in general, have occafion to be taught in the most expeditious manner. In fact, we find very few treatifes drawn up in this method, exceptelementary ones, for the use of students, and particularly in pure mathematics and philosophy.

#

[ocr errors]

The generality of writers deliver their fentiments to the public upon subjects of speculation in a looser and very different method. Far from always laying down propofitions, and then entering upon the proof of them, they as frequently begin with obfervations or experiments, and fhow how they lead to the principles they intend to establish: or, in a treatise of a confiderable extent, they use sometimes the one, and fometimes the other me-" thod, naming the propofition before the proof, or the proof before the propofition, as they imagine the one or the other will introduce their fentiments with the most advantage, and make their performance the most agreeable to their readers.

As

« AnteriorContinua »