eral 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. 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.

191. 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.-But 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. Al though 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 than one who might take it into his head to doubt of the propositions of Euclid.-It is this very high degree of probability which we term moral certainty.

§ 192. 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 resemblance 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. 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. It is nevertheless true, that much care is necessary in arguments drawn from this source, especially in scientific investigations. The proper use of analogical reasoning in scientific inquiries seems to be, merely to illustrate and confirm truths which are susceptible of proof from other sources of evidence, either by casting a direct additional light or by answering objections.

193. Of reasoning by induction.

We now come 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 moral certainty; and is at least found to be sufficient for all practical purposes. We obtain all the general truths relating to the properties and laws of material objects in this way.

And we thus not only acquire a knowledge of material objects, but apply the same inductive process also in the investigation of laws which govern the operations of the mind. It is by experience, or observing what takes place in a number of individuals, that we are able to infer the general law of association, viz., when two or more ideas have existed in the mind in immediate succession, they are afterward found to be mutually suggested by each other. It is the same in ascertaining other general laws

of the mind.

194. Of combined or accumulated arguments.

When a proposition in geometry is given to be demonstrated, it sometimes happens that two or more solutions may be offered leading to the same end. The theorem or the problem is one and the same, as also the conclusion; but there may be more than one train of reasoning, more than one series of intermediate steps connecting the proposition which is to be investigated with the result. But as the conclusion in each of these different cases is certain, it does not strengthen it, although it may gratify curiosity to resort to a different and additional process.

It is not thus in moral reasoning. The great difference between the two kinds of reasoning, as before observed, is not so much in the mental process as in the subjects about which they are employed. Now, as the subjects in moral reasoning are not of a purely abstract nature, and are, therefore, often attended with uncertainty, our belief, when we arrive at the conclusion, is not always of the highest kind. More frequently it is some inferior degree of probability. Hence, in any moral inquiry, the more numerous the series of arguments which terminates in a particular conclusion, the stronger will be our belief in the truth of that conclusion.

Thus we may suppose a question to arise, Whether the Romans occupied the island of Great Britain at some period previous to the Saxon conquest? In reference to this inquiry a number of independent arguments may be brought forward. (1.) The testimony of the Roman historians. (2.) The remains of buildings, roads, and encampments, which indicate a Roman origin. (3.) The coins, urns, &c., which have been discovered. Although these arguments are independent of each other, they all bear upon the same conclusion; and, being combined together, they very essentially increase the strength of our belief.

CHAPTER XII.

PRACTICAL DIRECTIONS IN REASONING.

195. Rules relating to the practice of reasoning.

VARIOUS directions have been given by writers on Logic, (which, it may be remarked here, is only another name for whatever concerns the nature, kinds, and applications of Reasoning,) the object of which is to secure the more prompt, accurate, and efficient use of the reasoning power. It is but natural to suppose, that some of these dialectical rules are of greater, and others of less value. Such as appeared to be of the least questionable importance, are brought together and explained in this chapter; nor will this occasion any surprise, when it is recollected that it has been the object of this work throughout, not only to ascertain what the mental operations are, but, by practical suggestions from time to time, to promote what is of a good, and prevent what is of a hurtful tendency in such operations.

The directions now referred to have, of course, a more intimate connexion with Moral than with Demonstrative reasoning; but this is a circumstance which enhances rather than diminishes their worth. The occasions which admit and require the application of moral reasoning, being inseparable from the most common occurrences and exigences of life, are much more numerous than those of demonstrative reasoning.

§ 196. Of being influenced in reasoning by a love of the truth. (I.) The first direction in relation to reasoning which will be given, concerns the feelings with which it is proper to be animated. It is this. In all questions which admit of discussion, and on which we find ourselves at variance with the opinions of others, we are to make truth our object. The opposite of a desire of the truth is a wish to decide the subject of dispute in one way rather than another, independently of a just consideration of the evi