The fountain of all virtue is manifestly the life according to nature; as being the life of subordination of self to more general interests—­to family, country, mankind, the whole universe.  If a man is prepared to consider himself absolutely nothing in comparison with the universal interest, and to regard it as the sole end of life, he has embraced an ideal of virtue of the loftiest order.  Accordingly, the Stoics were the first to preach what is called ‘Cosmopolitanism;’ for although, in their reference to the good of the whole, they confounded together sentient life and inanimate objects—­rocks, plants, &c., solicitude for which was misspent labour—­yet they were thus enabled to reach the conception of the universal kindship of mankind, and could not but include in their regards the brute creation.  They said:  ’There is no difference between the Greeks and Barbarians; the world is our city.’  Seneca urges kindness to slaves, for ’are they not men like ourselves, breathing the same air, living and dying like ourselves?’

The Epicureans declined, as much as possible, interference in public affairs, but the Stoic philosophers urged men to the duties of active citizenship.  Chrysippus even said that the life of philosophical contemplation (such as Aristotle preferred, and accounted godlike) was to be placed on the same level with the life of pleasure; though Plutarch observes that neither Chrysippus nor Zeno ever meddled personally with any public duty; both of them passed their lives in lecturing and writing.  The truth is that both of them were foreigners residing at Athens; and at a time when Athens was dependent on foreign princes.  Accordingly, neither Zeno nor Chrysippus had any sphere of political action open to them; they were, in this respect, like Epictetus afterwards—­but in a position quite different from Seneca, the preceptor of Nero, who might hope to influence the great imperial power of Rome, and from Marcus Antoninus, who held that imperial power in his own hands.

Marcus Antoninus—­not only a powerful Emperor, but also the most gentle and amiable man of his day—­talks of active beneficence both as a duty and a satisfaction.  But in the creed of the Stoics generally, active Beneficence did not occupy a prominent place.  They adopted the four Cardinal Virtues—­Wisdom, or the Knowledge of Good and Evil; Justice; Fortitude; Temperance—­as part of their plan of the virtuous life, the life according to Nature.  Justice, as the social virtue, was placed above all the rest.  But the Stoics were not strenuous in requiring more than Justice, for the benefit of others beside the agent.  They even reckoned compassion for the sufferings of others as a weakness, analogous to envy for the good fortune of others.