This circumstance in the structure of the human understanding is well known, and is the foundation of many provisions that occur in the constitution of political society. How each man shall form his creed, and arrange those opinions by which his conduct shall be regulated, is of course a matter exclusively subjected to his own discretion. But, when he is called upon to act in the name of a community, and to decide upon a question in which the public is interested, he of necessity feels himself called upon to proceed with the utmost caution. A judge on the bench, a chancellor, is not contented with that sudden ray of mental illumination to which an ingenuous individual is often disposed to yield in an affair of abstract speculation. He feels that he is obliged to wait for evidence, the nature of which he does not yet anticipate, and to adjourn his decision. A deliberative council or assembly is aware of the necessity of examining a question again and again. It is upon this principle that the two houses of the English parliament are required to give a first, a second and a third reading, together with various other forms and technicalities, to the provision that is brought before them, previously to its passing into a law. And there is many a fundamental dogma and corner-stone of the sentiments that I shall emphatically call my own, that is of more genuine importance to the individual, than to a nation is a number of those regulations, which by courtesy we call acts of parliament.
Nothing can have a more glaring tendency to subvert the authority of my opinion among my fellow-men, than instability. "What went ye out into the wilderness to see" said Jesus Christ: "a reed shaken with the wind?" We ought at all times to be open to conviction. We ought to be ever ready to listen to evidence.
But, conscious of our human frailty, it is seldom that we ought immediately to subscribe to the propositions, however specious, that are now for the first time presented to us. It is our duty to lay up in our memory the suggestions offered upon any momentous question, and not to suffer them to lose their inherent weight and impressiveness; but it is only through the medium of consideration and reconsideration, that they can become entitled to our full and unreserved assent.
The nature of belief, or opinion, has been well illustrated by Lord Shaftesbury[32]. There are many notions or judgments floating in the mind of every man, which are mutually destructive of each other. In this sense men's opinions are governed by high and low spirits, by the state of the solids and fluids of the human body, and by the state of the weather. But in a paramount sense that only can be said to be a man's opinion which he entertains in his clearest moments, and from which, when he is most himself, he is least subject to vary. In this emphatical sense, I should say, a man does not always know what is his real opinion. We cannot strictly be said to believe any thing, in cases where we afterwards change our opinion without the introduction of some evidence that was unknown to us before. But how many are the instances in which we can be affirmed to be in the adequate recollection of all the evidences and reasonings which have at some time occurred to us, and of the opinions, together with the grounds on which they rested, which we conceived we had justly and rationally entertained?
The considerations here stated however should by no means be allowed to inspire us with indifference in matters of opinion.
It is the glory and lustre of our nature, that we are capable of receiving evidence, and weighing the reasons for and against any important proposition in the balance of an impartial and enlightened understanding. The only effect that should be produced in us, by the reflection that we can at last by no means be secure that we have attained to a perfect result, should be to teach us a wholsome diffidence and humility, and induce us to confess that, when we have done all, we are ignorant, dim-sighted and fallible, that our best reasonings may betray, and our wisest conclusions deceive us.
[32] Enquiry concerning Virtue, Book 1, Part 1, Section ii.