CHAPTER TWENTY SIXTH.

MORAL REASONING.

§. 298. Of the subjects and importance of moral reasoning. MORAL ORAL REASONING, which is the second great division or kind of reasoning, concerns opinions, actions, events &c.; embracing in general those subjects, which do not come within the province of demonstrative reasoning. The subjects, to which it relates, are often briefly expressed by saying, that they are matters of fact; nor would this definition, concise as it is, be likely to give an erroneous idea of them. Skill in this kind of reasoning is of great use in the formation of opinions concerning the duties, and the general conduct of life. Some may be apt to think, that those, who have been most practised in demonstrative reasoning, can find no difficulty in adapting their intellectual habits to matters of mere probability. This opinion is not altogether well founded, as we have seen in the preceding chapter. Although that species of reasoning has a favourable result in giving persons a command over the attention, and in some other respects, whenever exclusively employed it has the effect in some degree to disqualify them for a correct judgment on those various subjects. which properly belong to moral reasoning.--The last. therefore, which has its distinctive name from the primary signification of the Latin MORES, viz. manners, customs, &c. requires a separate consideration.

§. 299. Of the nature of moral certainty.

Moral reasoning causes in us different degrees of assent, and in this respect differs from demonstrative. In demonstration there is not only an immediate perception of the relation of the propositions compared together; but in consequence of their abstract and determinate nature, there is also a knowledge or absolute certainty of their agreement or disagreement. In moral reasoning the case is somewhat different.--In both kinds we begin with certain propositions, which are either known or regarded as such. In both there is a series of propositions successively compared. But in moral reasoning, in consequence of the propositions not being abstract and fixed, and, therefore, often uncertain, the agreement or disagreement among them is in general not said to be known, but presumed; and this presumption may be more or less, admitting a great variety of degrees. While, therefore, one mode of reasoning is attended with knowledge; the other can properly be said to produce in most cases only judgment or opinion.-3ut the probability of such judgment or opinion may sometimes arise so high, as to exclude all reasonable doubt. And hence we then speak, as if we possessed certainty in respect to subjects, which admit merely of the application of moral reasoning. Although it is possible, that there may be some difference between the belief attendant on demonstration, and that produced by the highest probability, the effect on our feelings is at any rate essentially the same. A man, who should doubt the existence of the cities of London and Pekin, although he has no other evidence of it than that of testimony, would be considered hardly less singular and unreasonable, that one, who might take it into his head to doubt of the truth of the propositions of Euclid.-It is this very high degree of probability, which we term moral certainly.

§. 300. Of reasoning from analogy.

MORAL REASONING admits of some subordinate divisions; and of these, the first to be mentioned is reasoning from analogy. The word, analogy, is used with some vagueness,

but in general denotes a resemblance, either greater or less. Having observed a consistency and 'uniformity in the operations of the physical world, we are naturally led to presume, that things of the same nature will be affected in the same way, and will produce the same effects; and also that the same or similar effects are to be attributed to like causes. ANALOGICAL REASONING, therefore, is that mental process, by which unknown truths or conclusions are inferred from the resemblances of things.

The argument, by which Sir Isaac Newton establishes the truth of universal gravitation, is of this sort. He proves, that the planets in their revolutions are deflected towards the sun in a manner precisely similar to the deflection of the earth towards the same luminary; and also that there is a similar deflection of the moon towards the earth, and of a body projected obliquely at the earth's surface towards the earth's centre. Hence he infers by analogy, that all these deflections originate from the same cause, or are governed by one and the same law, viz. the power of gravitation.

This method of reasoning is applicable to the inquiry, Whether the planets are inhabited? and furnishes the sole ground for the indulgence of such a supposition. We observe a resemblance in certain respects between Mars, Jupiter, Saturn, and other planets, and the earth. They all revolve around the sun, as the earth does, and all derive light from that source. Several of them are ascertained to revolve on their axis, and, consequently, must have a succession of day and night. Some of them have moons, and all are subject to the law of gravitation. From these various similitudes we draw the conclusion by analogy, that those planets must be inhabited, like the earth.

There are a variety of subjects, both speculative and practical, in respect to which we may reason in this way: and sometimes with considerable satisfaction. And among others, this method of reasoning finds a place in the arguments of persons in the practice of the law. An attorney, for instance, advocates a case, which does not fall withi the provisions of existing statutes, and for which he finds

in his authorities no exact precedent. He is, therefore, under the necessity of ascertaining, as far as possible, the analogy or resemblance between this case and others, which are given, and have been decided upon. And he has here a favourable opportunity for the exhibition of his research and discrimination.—A considerable part of the argumentation among pleaders at the bar is employed in urging various analogies of this sort. It is the business of the court in such instances to adjust, and compare them together, and allow them their due weight. In doing this, their discernment and integrity are called into exercise; for sometimes a small circumstance, and perhaps one, which the pleader has laboured to involve in obscurity, will disclose an essential distinction between the case in band, and that on the file of precedents, to which it has been likened.

§301. Caution to be used in reasoning from analogy.

The last remark leads us to observe, that much care is necessary in arguments drawn from this source, especially in scientific investigations; and they are in all cases to be received with some degree of distrust. The ancient anatomists are an instance of precipitate reasoning from analogy. Being hindered by certain superstitions from dissecting the bodies of men, they endeavoured to obtain the information they wanted, by the dissection of those animals, whose internal structure was supposed to come nearest to that of the human body. In this way they were led into a variety of mistakes, which have been detected by later anatomists. It does not follow, because things resemble each other in a number of particulars, that this resemblance will be found in all others; and we are, therefore, always to consider ourselves in danger of pushing the supposition of similitude too far.

The proper use of analogical reasoning seems to be, in all scientific inquiries, to illustrate and confirm truths, which are susceptible of proof from other sources of evidence. A happy instance of this use of it is the work of Bishop Butler, entitled, "The Analogy of Religion, natural

and revealed, to the Constitution and Course of nature."--It is not the object of the writer to prove the truth of religion, either natural or revealed, but to answer some objections, which may be brought against its principles. And this he does by proving, that the same objections exist to the providence of God in the natural world. There is an analogy or resemblance in the two; and if the objections, which are brought, will reject him from the authorship of what we term religion, either natural or revealed, they will dethrone him also from all direction in the ordinary economy of nature.

. 302. Of reasoning by induction.

We come now to another method of moral reasoning, viz. by induction. Inductive reasoning is the inferring of general truths from particular facts, that have fallen under our observation. Our experience teaches us, that nature is governed by uniform laws; and we have a firm expectation, (whether it be an original principle of our constitution or whatever may be the origin of it,) that events will happen in future, as we have seen them happen in times past. With this state of mind we are prepared to deduce inferences by induction.

When a property has been found in a number of subjects of the same kind, and nothing of a contradictory nature appears, we have the strongest expectation of finding the same property in all the individuals of the same class; in other words, we come to the conclusion, that the property is a general one. Accordingly, we apply a magnet to several pieces of iron; we find in every instance a strong attraction taking place; and we conclude, although we have made the experiment with only a small number of the masses of iron actually in existence, that it is a property of iron to be thus affected by that substance, or that all iron is susceptible of magnetical attraction. This is a conclusion drawn by induction.

The belief, which attends a well conducted process of inductive reasoning, bears a decided character; it is moral probability of the highest kind, or what is sometimes termed