280

OXFORD ENGLISH PRIZE ESSAY, FOR 1822.

THE STUDY OF MORAL EVIDENCE.

Fidei dentur quæ fidei sunt.-DE AUGMENTIS.

THE attainment of truth is, or ought to be, the great object of our intellectual pursuits, which are important only as they fit us to discharge with propriety the parts we are severally called to act. But as we are very liable to be deceived, this attainment involves an investigation into the tests by which we may discriminate between truth and error, and learn to recognise the one while we reject the other: in other words, it involves an inquiry into the nature of evidence in general, and the peculiarities which distinguish the different forms of proof which the human mind is capable of receiving.

All evidence may be reduced into the two great classes of demonstrative and moral. It is with the former exclusively that the mathematician is conversant, and his deductions are generally considered to possess the merit of absolute certainty; a claim which has not been conceded to the moral reasoner, whose arguments must all be derived from probabilities; and these, it is generally conceived, can never, by any possible accumulation, amount to such certainty as that which attends the study of demonstrative truth.

It is not indeed surprising, that demonstrative evidence should have received the preference of scientific men, who could not fail to admire the luminous precision of its language, the secure and elegant process of its reasoning, and the incontrovertible certainty of its results. Nothing can be more satisfactory, either to the sincere disciple of truth, or the indolent speculator, than to be conducted to complete conviction by an irresistible impulse which at once removes the danger of falling into a single fallacy, and precludes the necessity of ascertaining the relative value of contradictory arguments.

The manifest defect, however, of such reasoning is, that, though it may serve to carry on the abstract investigations of the philosopher, it is inapplicable to by far the greater part of our actual occupations. Whatever estimate, on the contrary, we may form of the credit due to moral evidence,

this at least is certain, that it is on probabilities alone that we build those conclusions which carry us through the practical detail of life.

The pure mathematics are extremely confined in their operation, and by themselves would be of no ultimate utility beyond the mere exercise of the reasoning powers; and we shall have occasion to observe hereafter, that even in this respect their advantage is limited and equivocal.

Though our knowledge, for instance, of the laws which regulate the physical phenomena of the universe can only be reduced to the precision of science by the application of mathematical proof, yet it is not by the cautious and shortsighted process of demonstration, that genius has been able to extend the boundaries of our knowledge by the discovery of those laws, and thus to introduce the mathematician to subjects of contemplation with which he must otherwise have remained for ever unacquainted. We view with just admiration the discoveries which Newton made of the laws which prevail throughout the boundless extent of space; but the basis of the lofty fabric he has reared is an assumption of which there is no proof but in analogy,-the lowest species of moral evidence. We observe that, as far as our experience reaches, when a body is impelled from an elevated station, it tends towards the earth with an uniformly accelerated velocity; but what certainty have we that the laws of gravity, which we cannot demonstrate to be universally applicable even to the earth we inhabit, have any existence whatever in regions so far removed from our observation? We find, indeed, that on these principles we can account for the motions of the heavenly bodies, and that, assuming gravity as a datum, all our subsequent calculations may be conducted with the utmost degree of mathematical precision. But this coincidence may, for any thing we can demonstrate to the contrary, be purely accidental, and have no more real connexion with those phenomena than that of a key with the lock which it happens to fit, but for which it was not originally designed.

All such assumptions, though founded on the most comprehensive induction, would be at once rejected as uncertain by the mere geometrician. But the "subtilty of nature," in its turn, rejects his uncompromising precision, and will not exhibit its wonders but to the disciple of a more tolerant philosophy. Without the aid of moral reasoning, science must for ever be confined to the unprofitable office of evol

ving the abstract relations of quantity, and even with its assistance can apply only to the grosser properties of the visible creation. When, however, we pursue our investigations into the composition and natural history of the earth on which we move, and attempt to explain the appearances it exhibits; when we examine the affinities of different substances with each other, or indulge in speculations respecting the phenomena which are constantly taking place around us, we must be content with such evidence as probability affords; for these subjects, in all their extensive and interesting detail, will not submit to strict demonstration.

Still more is this the case, when from the inanimate we turn to the sensitive part of the creation. No sooner do we arrive at the noblest and most comprehensive study to which our faculties can be directed, and make the mind of man the object of our research, than we are deserted entirely by demonstration. It is by moral evidence alone that the historian brings us acquainted with the times that are past, and that the divine supplies us with information respecting the future; it is by this that the orator hurries along our judgment to his own conclusions, that the poet charms us into wisdom, and the philosopher accounts for the influence of both. Though we may form a precise idea of a right line, as that which lies evenly between its extreme points, we cannot demonstrate what course of conduct duty may require or wisdom dictate; and he would be very far from possessing a sufficient moral rule, who might have been merely told that virtue is the mean between opposite vices. Whenever, in one word, we consider man as a reasonable and responsible agent, we argue on moral evidence, and find the mathematics not only inapplicable, but even unfriendly to our inquiries. It is the pride of that jealous science to exclude the influence of every part of our spiritual constitution which is not essential to the simple exercise of reason. With all the finer sensibilities of our nature, with our hopes and fears, our joys and griefs, our antipathies and predilections, the affections which bind us to each other, and the passions which modify or cement our intercourse, it holds no alliance, but rather rejects them as so many impediments to the attainment of truth. While, however, demonstration, entrenched within this narrow boundary, is incompetent to investigate the phenomena of mind, and unable to turn to any account our various mental energies, the

moral philosopher is restrained only by the limits of the intellectual universe, and avails himself of every modification of feeling and shade of character, considering them as subservient to his sublime investigations.

This association with sentiment, however, has frequently been urged, even by those who admit the extensive influence of moral evidence, as a prominent objection to its intrinsic worth. Accurate men have been forward to complain, that the understanding is too much under the influence of feeling, and we often find them expressing a hope that at some future period a language may be invented better adapted for philosophical purposes, and bearing some resemblance to the algebraical calculus.' The most obvious

answer to such remarks is drawn from the necessity of the case. It certainly were to be wished that we could be in any degree emancipated from the tyranny which words exercise over our ideas, as well as from that of passion over our judgment. But even this, though it would give greater stability to moral reasoning, would not extend the department of strict demonstration; and as long as human nature is the same, we must expect that passion, under all its forms, will retain its power, though circumstances may limit its exercise. The line which marks the boundaries of mathematical precision must ever continue the same, and throughout the wide extent of unappropriated territory which lies beyond it, moral evidence will still remain as the only criterion of truth, and the only medium of investigation. Here we shall be exposed to the same imperfections which now retard our advancement in knowledge; we shall be often blinded by prejudice, misdirected by false feeling, bewildered among the unsubstantial creations of fancy, and cheated by the ingenious fallacies of sophistical But since declamation. we can rule nature only by obedience," it is of great moment to ascertain by all possible means the laws according to which she proceeds. is, however, the province of the moral reasoner, and it belongs to him exclusively. It is he alone who can pene trate the human breast, and sweep at will the chords of sympathy till they respond to every emotion he may be anxious to excite. Whether the imagination be imme

66

This

See the Essay on the Human Understanding, 1. iv. c. 3. s. 18. l. iv. c. 12. s. 7. &c.

diately addressed by the fascinations of poetry and eloquence, or our judgment assailed under the more imposing form of logical precision, still demonstration, at least what is usually considered such, is absolutely excluded; the utmost we can assert of any evidence we bring forward on such subjects is, that it bears the marks of a greater or less degree of probability, and the sum of our proof can amount only to such conviction as must result from the aggregate influence of these probabilities on the mind.

Are we then to conclude that our real knowledge is confined to the properties of curves and angles, while in the vast field of interesting inquiry over which, as we have seen, moral evidence extends, we can only wander about in uncertainty, and indulge in plausible conjectures? Most assuredly, if scientific demonstration be the sole criterion of truth, we must acknowledge, however melancholy the concession would be, that we are ignorant of all that concerns our best and dearest interests. For since moral evidence comprises almost every subject about which our faculties can be engaged, from the most ordinary topics of common life to the highest mysteries of religion, the present discussion is not a merely speculative inquiry, but assumes a character of vast practical importance; the question involved in it being not simply, whether we will submit to have our intellectual estate wrested from us in consequence of some flaw in the title-deed, and the garniture of our mind stripped off by the wand of a magician, who would persuade us that all in which we gloried is void of substance; but whether we will consent to give up the only light which can guide, the only staff which can support us through the regions of infinity?

But is this the only alternative; and is it not possible that moral evidence, at least in its most perfect form, may lead us to a species of certainty fully equivalent, in the conviction which it imparts, to mathematical demonstration, though differing from it in some important respects, and particularly in the process by which it is attained?

In the first place, what is the amount of that demonstrative certainty, as it is called, with which those who reject the authority of moral reasoning profess to be satisfied? Is the former so essentially superior to the latter as to be altogether free from exception, even when subjected to a minute analysis, on the strict, and, as we hope to prove, illegitimate principles of sceptical philosophers?