From Book I, Chapter 4
First of all, Nature has endowed every species of living creature with the instinct of self-preservation, of avoiding what seems likely to cause injury to life or limb, and of procuring and providing everything needful for life -- food, shelter, and the like. A common property of all creatures is also the reproductive instinct (the purpose of which is the propagation of the species) and also a certain amount of concern for their offspring. But the most marked difference between man and beast is this: the beast, just as far as it is moved by the senses and with very little perception of past or future, adapts itself to that alone which is present at the moment; while man -- because he is endowed with reason, by which he comprehends the chain of consequences, perceives the causes of things, understands the relation of cause to effect and of effect to cause, draws analogies, and connects and associates the present and the future -- easily surveys the course of his whole life and makes the necessary preparations for its conduct.
---------------
Above all, the search after truth and its eager pursuit are peculiar to man. And so, when we have leisure from the demands of business cares, we are eager to see, to hear, to learn something new, and we esteem a desire to know the secrets or wonders of creation as indispensable to a happy life. Thus we come to understand that what is true, simple, and genuine appeals most strongly to a man's nature. To this passion for discovering truth there is added a hungering, as it were, for independence, so that a mind well-moulded by Nature is unwilling to be, subject to anybody save one who gives rules of conduct or is a teacher of truth or who, for the general good, rules according to justice and law. From this attitude come greatness of soul and a sense of superiority to worldly conditions.
And it is no mean manifestation of Nature and Reason that man is the only animal that has a feeling for order, for propriety, for moderation in word and deed. And so no other animal has a sense of beauty, loveliness, harmony in the visible world; and Nature and Reason, extending the analogy of this from the world of sense to the world of spirit, find that beauty, consistency, order are far more to be maintained in thought and deed, and the same Nature and Reason are careful to do nothing in an improper or unmanly fashion, and in every thought and deed to do or think nothing capriciously. It is from these elements that is forged and fashioned that moral goodness which is the subject of this inquiry -- something that, even though it be not generally ennobled, is still worthy of all honour; and by its own nature, we correctly maintain, it merits praise even though it be praised by none.
From Book I, Chapter 5
You see here, Marcus, my son, the very form and as it were the face of Moral Goodness; "and if," as Plato says, "it could be seen with the physical eye, it would awaken a marvellous love of wisdom." But all that is morally right rises from some one of four sources: it is concerned either (1) with the full perception and intelligent development of the true; or (2) with the conservation of organized society, with rendering to every man his due, and with the faithful discharge of obligations assumed; or (3) with the greatness and strength of a noble and invincible spirit; or (4) with the orderliness and moderation of everything that is said and done, wherein consist temperance and self-control.
Although these four are connected and interwoven, still it is in each one considered singly that certain definite kinds of moral duties have their origin: in that category, for instance, which was designated first in our division and in which we place wisdom and prudence, belong the search after truth and its discovery; and this is the peculiar province of that virtue. For the more clearly anyone observes the most essential truth in any given case and the more quickly and accurately he can see and explain the reasons for it, the more understanding and wise he is generally esteemed, and justly so. So, then, it is truth that is, as it were, the stuff with which this virtue has to deal and on which it employs itself.
Before the three remaining virtues, on the other hand, is set the task of providing and maintaining those things on which the practical business of life depends so that the relations of man to man in human society may be conserved, and that largeness and nobility of soul may be revealed not only in increasing one's resources and acquiring advantages for one's self and one's family but far more in rising superior to these very things. But orderly behaviour and consistency of demeanor and self-control and the like have their sphere in that department of things in which a certain amount of physical exertion, and not mental activity merely, is required. For if we bring a certain amount of propriety and order into the transactions of daily life, we shall be conserving moral rectitude and moral dignity.
From Book I, Chapter 16
The interests of society, however, and its common bonds will be best conserved, if kindness be shown to each individual in proportion to the closeness of his relationship. But it seems we must trace back to their ultimate sources the principles of fellowship and society that Nature has established among men. The first principle is that which is found in the connection subsisting between all the members of the human race; and that bond of connection is reason and speech, which by the processes of teaching and learning, of communicating, discussing, and reasoning associate men together and unite them in a sort of natural fraternity. In no other particular are we farther removed from the nature of beasts; for we admit that they may have courage (horses and lions, for example); but we do not admit that they have justice, equity, and goodness; for they are not endowed with reason or speech. This, then, is the most comprehensive bond that unites together men as men and all to all; and under it the common right to all things that Nature has produced for the common use of man is to be maintained, with the understanding that, while everything assigned as private property by the statutes and by civil law shall be so held as prescribed by those same laws, everything else shall be regarded in the light indicated by the Greek proverb: "Amongst friends all things in common."
From Book I, Chapter 17
Then, too, there are a great many degrees of closeness or remoteness in human society. To proceed beyond the universal bond of our common humanity, there is the closer one of belonging to the same people, tribe, and tongue, by which men are very closely bound together; it is a still closer relation to be citizens of the same city-state; for fellow-citizens have much in common -forum, temples colonnades, streets, statutes, laws, courts, rights of suffrage, to say nothing of social and friendly circles and diverse business relations with many. But a still closer social union exists between kindred. Starting with that infinite bond of union of the human race in general, the conception is now confined to a small and narrow circle. For since the reproductive instinct is by Nature's gift the common possession of all living creatures, the first bond of union is that between husband and wife; the next, that between parents and children; then we find one home, with everything in common. And this is the foundation of civil government, the nursery, as it were, of the state. Then follow the bonds between brothers and sisters, and next those of first and then of second cousins; and when they can no longer be sheltered under one roof, they go out into other homes, as into colonies. Then follow between these in turn, marriages and connections by marriage, and from these again a new stock of relations; and from this propagation and after-growth states have their beginnings. The bonds of common blood hold men fast through good-will and affection; for it means much to share in common the same family traditions the same forms of domestic worship, and the same ancestral tombs. But of all the bonds of fellowship, there is none more noble, none more powerful than when good men of congenial character are joined in intimate friendship; for really, if we discover in another that moral goodness on which I dwell so much, it attracts us and makes us friends to the one in whose character it seems to dwell. And while every virtue attracts us and makes us love those who seem to possess it, still justice and generosity do so most of all.
From Book I, Chapter 30
But it is essential to every inquiry about duty that we keep before our eyes how far superior man is by nature to cattle and other beasts: they have no thought except for sensual pleasure and this they are impelled by every instinct to seek; but man's mind is nurtured by study and meditation; he is always either investigating or doing, and he is captivated by the pleasure seeing and hearing. Nay, even if a man is more than ordinarily inclined to sensual pleasures, provided, of course, that he be not quite on a level with the beasts of the field (for some people are men only in name, not in fact) -- if, I say, he is a little too susceptible to the attractions of pleasure, he hides the fact, however much he may be caught in its toils, and for very shame conceals his appetite.
From this we see that sensual pleasure is quite unworthy of the dignity of man and that we ought to despise it and cast it from us; but if someone should be found who sets some value upon sensual gratification, he must keep strictly within the limits of moderate indulgence. One's physical comforts and wants, therefore, should be ordered according to the demands of health and strength, not according to the calls of pleasure. And if we will only bear in mind the superiority and dignity of our nature, we shall realize how wrong it is to abandon ourselves to excess and to live in luxury and voluptuousness, and how right it is to live in thrift, self-denial, simplicity, and sobriety.
We must realize also that we are invested by Nature with two characters [= roles, personae], as it were: one of these is universal, arising from the fact of our being all alike endowed with reason and with that superiority which lifts us above the brute. From this all morality and propriety are derived, and upon it depends the rational method of ascertaining our duty. The other character [= role, persona] is the one that is assigned to individuals in particular. In the matter of physical endowment there are great differences: some, we see, excel in speed for the race, others in strength for wrestling; so in point of personal appearance, some have stateliness, others comeliness.
From Book I, Chapter 31
Everybody, however, must resolutely hold fast to his own peculiar gifts [= the second character/role/persona], in so far as they are peculiar only and not vicious, in order that propriety, which is the object of our inquiry, may the more easily be secured. For we must so act as not to oppose the universal laws of human nature [= the first character/role/persona], but, while safeguarding those, to follow the bent of our own particular nature [= the second character/role/persona]; and even if other careers should be better and nobler, we may still regulate our own pursuits by the standard of our own nature. For it is of no avail to fight against one's nature or to aim at what is impossible of attainment. From this fact the nature of that propriety defined above comes into still clearer light, inasmuch as nothing is proper that "goes against the grain," as the saying is -- that is, if it is in direct opposition to one's natural genius.
If there is any such thing as propriety at all, it can be nothing more than uniform consistency in the course of our life as a whole and all its individual actions. And this uniform consistency one could not maintain by copying the personal traits of others and eliminating one's own. For as we ought to employ our mother-tongue, lest, like certain people who are continually dragging in Greek words, we draw well-deserved ridicule upon ourselves, so we ought not to introduce anything foreign into our actions or our life in general. Indeed, such diversity of character carries with it so great significance that suicide may be for one man a duty, for another [under the same circumstances] a crime. Did Marcus Cato find himself in one predicament, and were the others, who surrendered to Caesar in Africa, in another? And yet, perhaps, they would have been condemned, if they had taken their lives; for their mode of life had been less austere and their characters more pliable. But Cato had been endowed by nature with an austerity beyond belief, and he himself had strengthened it by unswerving consistency and had remained ever true to his purpose and fixed resolve; and it was for him to die rather than to look upon the face of a tyrant.
From Book I, Chapter 32
To the two above-mentioned characters [= roles, personae] is added a third, which some chance or some circumstance imposes, and a fourth also, which we assume by our own deliberate choice. Regal powers and military commands, nobility of birth and political office, wealth and influence, and their opposites depend upon chance and are, therefore, controlled by circumstances. But what role we ourselves may choose to sustain is decided by our own free choice. And so some turn to philosophy, others to the civil law, and still others to oratory, while in case of the virtues themselves one man prefers to excel in one, another in another.