The same theory, that accounts for the love of truth in mathematics and algebra may be extended to morals, politics, natural philosophy, and other studies, where we consider not the other abstract relations of ideas, but their real connexions and existence. But beside the love of knowledge, which displays itself in the sciences, there is a certain curiosity implanted in human nature, which is a passion derived from a quite different principle. Some people have an insatiable desire of knowing the actions and circumstances of their neighbours, though their interest be no way concerned in them, and they must entirely depend on others for their information; in which case there is no room for study or application. Let us search for the reason of this phænomenon.
It has been proved at large, that the influence of belief is at once to inliven and infix any idea in the imagination, and prevent all kind of hesitation and uncertainty about it. Both these circumstances are advantageous. By the vivacity of the idea we interest the fancy, and produce, though in a lesser degree, the same pleasure, which arises from a moderate passion. As the vivacity of the idea gives pleasure, so its certainty prevents uneasiness, by fixing one particular idea in the mind, and keeping it from wavering in the choice of its objects. It is a quality of human nature, which is conspicuous on many occasions, and is common both to the mind and body, that too sudden and violent a change is unpleasant to us, and that however any objects may in themselves be indifferent, yet their alteration gives uneasiness. As it is the nature of doubt to cause a variation in the thought, and transport us suddenly from one idea to another, it must of consequence be the occasion of pain. This pain chiefly takes place, where interest, relation, or the greatness and novelty of any event interests us in it. It is not every matter of fact, of which we have a curiosity to be informed; neither are they such only as we have an interest to know. It is sufficient if the idea strikes on us with such force, and concerns us so nearly, as to give us an uneasiness in its instability and inconstancy. A stranger, when he arrives first at any town, may be entirely indifferent about knowing the history and adventures of the inhabitants; but as he becomes farther acquainted with them, and has lived any considerable time among them, he acquires the same curiosity as the natives. When we are reading the history of a nation, we may have an ardent desire of clearing up any doubt or difficulty, that occurs in it; but become careless in such researches, when the ideas of these events are, in a great measure, obliterated.
BOOK III OF MORALS
PART I OF VIRTUE AND VICE IN GENERAL
SECT. I MORAL DISTINCTIONS NOT DERIVED FROM REASON
There is an inconvenience which attends all abstruse reasoning that it may silence, without convincing an antagonist, and requires the same intense study to make us sensible of its force, that was at first requisite for its invention. When we leave our closet, and engage in the common affairs of life, its conclusions seem to vanish, like the phantoms of the night on the appearance of the morning; and it is difficult for us to retain even that conviction, which we had attained with difficulty. This is still more conspicuous in a long chain of reasoning, where we must preserve to the end the evidence of the first propositions, and where we often lose sight of all the most received maxims, either of philosophy or common life. I am not, however, without hopes, that the present system of philosophy will acquire new force as it advances; and that our reasonings concerning morals will corroborate whatever has been said concerning the UNDERSTANDING and the PASSIONS. Morality is a subject that interests us above all others: We fancy the peace of society to be at stake in every decision concerning it; and it is evident, that this concern must make our speculations appear more real and solid, than where the subject is, in a great measure, indifferent to us. What affects us, we conclude can never be a chimera; and as our passion is engaged on the one side or the other, we naturally think that the question lies within human comprehension; which, in other cases of this nature, we are apt to entertain some doubt of. Without this advantage I never should have ventured upon a third volume of such abstruse philosophy, in an age, wherein the greatest part of men seem agreed to convert reading into an amusement, and to reject every thing that requires any considerable degree of attention to be comprehended.
It has been observed, that nothing is ever present to the mind but its perceptions; and that all the actions of seeing, hearing, judging, loving, hating, and thinking, fall under this denomination. The mind can never exert itself in any action, which we may not comprehend under the term of perception; and consequently that term is no less applicable to those judgments, by which we distinguish moral good and evil, than to every other operation of the mind. To approve of one character, to condemn another, are only so many different perceptions.
Now as perceptions resolve themselves into two kinds, viz. impressions and ideas, this distinction gives rise to a question, with which we shall open up our present enquiry concerning morals. WHETHER IT IS BY MEANS OF OUR IDEAS OR IMPRESSIONS WE DISTINGUISH BETWIXT VICE AND VIRTUE, AND PRONOUNCE AN ACTION BLAMEABLE OR PRAISEWORTHY? This will immediately cut off all loose discourses and declamations, and reduce us to something precise and exact on the present subject.
Those who affirm that virtue is nothing but a conformity to reason; that there are eternal fitnesses and unfitnesses of things, which are the same to every rational being that considers them; that the immutable measures of right and wrong impose an obligation, not only on human creatures, but also on the Deity himself: All these systems concur in the opinion, that morality, like truth, is discerned merely by ideas, and by their juxta-position and comparison. In order, therefore, to judge of these systems, we need only consider, whether it be possible, from reason alone, to distinguish betwixt moral good and evil, or whether there must concur some other principles to enable us to make that distinction.
If morality had naturally no influence on human passions and actions, it were in vain to take such pains to inculcate it; and nothing would be more fruitless than that multitude of rules and precepts, with which all moralists abound. Philosophy is commonly divided into speculative and practical; and as morality is always comprehended under the latter division, it is supposed to influence our passions and actions, and to go beyond the calm and indolent judgments of the understanding. And this is confirmed by common experience, which informs us, that men are often governed by their duties, and are detered from some actions by the opinion of injustice, and impelled to others by that of obligation.