We "cannot quote from his own works, in his own words, because, although he wrote very much, only a summary of his writings has come to us uninjured; but his doctrines have been so fully investigated and treated on, both by his opponents and his disciples, that there is no difficulty or doubt as to the principles inculcated in the school of Epicurus.
"The sum of his doctrine concerning philosophy, in general, is this:—Philosophy is the exercise of reason in the pursuit and attainment of a happy life; whence it follows, that those studies which conduce neither to the acquisition nor the enjoyment of happiness are to be dismissed as of no value. The end of all speculation ought to be, to enable men to judge with certainty what is to be chosen, and what to be avoided, to preserve themselves free from pain, and to secure health of body, and tranquillity of mind. True philosophy is so useful to every man, that the young should apply to it without delay, and the old should never be weary of the pursuit; for no man is either too young or too old to correct and improve his mind, and to study the art of happiness. Happy are they who possess by nature a free and vigorous intellect, and who are born in a country where they can prosecute their inquiries without restraint: for it is philosophy alone which raises a man above vain fears and base passions, and gives him the perfect command of himself. As nothing ought to be dearer to a philosopher than truth, he should, pursue it by the most direct means, devising no actions himself, nor suffering himself to be imposed upon by the fictions of others, neither poets, orators, nor logicians, making no other use of the rules of rhetoric or grammar, than to enable him to speak or write with accuracy and perspicuity, and always preferring a plain and simple to an ornamented style. Whilst some doubt of everything, and others profess to acknowledge everything, a wise man will embrace such tenets, and only such as are built upon experience, or upon certain and indisputable axioms."
The following is a summary of his Moral Philosophy:—
"The end of living, or the ultimate good, which is to be sought for its own sake, according to the universal opinion of mankind, is happiness; yet men, for the most part, fail in the pursuit of this end, either because they do not form a right idea of the nature of happiness, or because they do not make use of proper means to attain it. Since it is every man's interest to be happy through the whole of life, it is the wisdom of every one to employ philosophy in the search of felicity without delay; and there cannot be a greater folly, than to be always beginning to live.
"The happiness which belongs to man, is that state in which he enjoys as many of the good things, and suffers as few of the evils incident to human nature as possible; passing his days in a smooth course of permanent tranquillity. A wise man, though deprived of sight or hearing, may experience happiness in the enjoyment of the good things which yet remain; and when suffering torture, or laboring under some painful disease, can mitigate the anguish by patience, and can enjoy, in bis afflictions, the consciousness of bis own constancy. But it is impossible that perfect happiness can be possessed without the pleasure which attends freedom from pain, and the enjoyment of the good things of life. Pleasure is in its nature good, as pain is in its nature evil; the one is, therefore, to be pursued, and the other to be avoided, for its own sake.—Pleasure, or pain, is not only good, or evil, in itself, but the measure of what is good or evil, in every object of desire or aversion; for the ultimate reason why we pursue one thing, and avoid another, is because we expect pleasure from the former, and apprehend pain from the latter. If we sometimes decline a present pleasure, it is not because we are averse to pleasure itself, but because we conceive, that in the present instance, it will be necessarily connected with a greater pain. In like manner, if we sometimes voluntarily submit to a present pain, it is because we judge that it is necessarily connected with a greater pleasure.—Although all pleasure is essentially good, and all pain essentially evil, it doth not thence necessarily follow, that in every single instance the one ought to be pursued, and the other to be avoided; but reason is to be employed in distinguishing and comparing the nature and degrees of each, that the result may be a wise choice of that which shall appear to be, upon the whole, good. That pleasure is the first good, appears from the inclination which every animal, from its first birth, discovers to pursue pleasure, and avoid pain; and is confirmed by the universal experience of mankind, who are incited to action by no other principle than the desire of avoiding pain, or obtaining pleasure. There are two kinds of pleasure: one consisting in a state of rest, in which both body and mind are undisturbed by any kind of pain; the other arising from an agreeable agitation of the senses, producing a correspondent emotion in the soul. It is upon the former of these that the enjoyment of life chiefly depends. Happiness may therefore be said to consist in bodily ease, and mental tranquillity, When pleasure is asserted to be the end of living, we are not then to understand that violent kind of delight or joy which arises from the gratification of the senses and passions, but merely that placid state of mind, which results from the absence of every cause of pain or uneasiness. Those pleasures, which arise from agitation, are not to be pursued as in themselves the end of living, but as means of arriving at that stable tranquillity, in which true happiness consists. It is the office of reason to confine the pursuit of pleasure within the limits of nature, in order to the attainment of that happy state, in which the body is free from every kind of pain, and the mind from all perturbation. This state must not, however, be conceived to be perfect in proportion as it is inactive and torpid, but in proportion as all the functions of life are quietly and pleasantly performed. A happy life neither resembles a rapid torrent, nor a standing pool, but is like a gentle stream, that glides smoothly and silently along.
"This happy state can only be obtained by a prudent care of the body, and a steady government of the mind. The diseases of the body are to be prevented by temperance, or cured by medicine, or rendered tolerable by patience. Against the diseases of the mind, philosophy provides sufficient antidotes. The instruments which it employs for this purpose are the virtues; the root of which, whence all the rest proceed, is prudence. This virtue comprehends the whole art of living discreetly, justly, and honorably, and is, in fact, the same thing with wisdom. It instructs men to free their understandings from the clouds of prejudice; to exercise temperance and fortitude in the government of themselves: and to practice justice towards others. Although pleasure, or happiness, which is the end of living, be superior to virtue, which is only the means, it is every one's interest to practice all the virtues; for in a happy life, pleasure can never be separated from virtue.
"A prudent man, in order to secure his tranquillity, will consult his natural disposition in the choice of his plan of life. If, for example, he be persuaded that he should be happier in a state of marriage than in celibacy, he ought to marry; but if he be convinced that matrimony would be an impediment to his happiness, he ought to remain single. In like manner, such persons as are naturally active, enterprising, and ambitious, or such as by the condition of their birth are placed in the way of civil offices, should accommodate themselves to their nature and situation, by engaging in public affairs; while such as are, from natural temper, fond of leisure and retirement, or, from experience or observation, are convinced that a life of public business would be inconsistent with their happiness, are unquestionably at liberty, except where particular circumstances call them to the service of their country, to pass their lives in obscure repose.
"Temperance is that discreet regulation of the desires and passions, by which we are enabled to enjoy pleasures without suffering any consequent inconvenience. They who maintain such a constant self-command, as never to be enticed by the prospect of present indulgence, to do that which will be productive of evil, obtain the truest pleasure by declining pleasure. Since, of desires some are natural and necessary; others natural, but not necessary; and others neither natural nor necessary, but the offspring of false judgment; it must be the office of temperance to gratify the first class, as far as nature requires: to restrain the second within the bounds of moderation; and, as to the third, resolutely to oppose, and, if possible, entirely repress them.
"Sobriety, as opposed to inebriety and gluttony, is of admirable use in teaching men that nature is satisfied with a little, and enabling them to content themselves with simple and frugal fare. Such a manner of living is conducive to the preservation of health: renders a man alert and active in all the offices of life; affords him an exquisite relish of the occasional varieties of a plentiful board, and prepares him to meet every reverse of fortune without the fear of want.
"Continence is a branch of temperance, which prevents the diseases, infamy, remorse, and punishment, to which those are exposed, who indulge themselves in unlawful amours. Music and poetry, which are often employed as incentives to licentious pleasure are to be cautiously and sparingly used.