The Lives and Opinions of Eminent Philosophers

by Diogenes Laertius

XLIV. In his dialogues he used to speak of justice as a kind of law of God, as being of influence sufficient to excite men to act justly, in order to avoid suffering punishment as malefactors after death. Owing to which he appeared to some people rather fond of mythical stories, as he mingled stories of this kind with his writings, in order by the uncertainty of all the circumstances that affect men after their death, to induce them to abstain from evil actions. And these were his opinions.

XLV. He used too, says Aristotle, to divide things in this manner:—Of good, some have their place in the mind, some in the body, and some are wholly external. As, for instance, justice, and prudence, and manly courage, and temperance, and qualities of that sort exist in the soul. Beauty, and a good constitution, and health, and strength exist in the body. But friends, and the prosperity of one’s country, and wealth, are external goods. There are then three species of goods, some in the soul, some in the body, and some external to either.

XLVI. There are also three species of friendship. For one kind is natural, another that which arises from companionship; and the third is that which is produced by ties of hospitality. We call that natural friendship which parents feel towards their offspring, and relations towards one another; and this is partaken of by other animals besides men. We call that the friendship of companionship which arises from a habit of association, and which has no reference to ties of blood, such as the friendship of Pylades for Orestes. That which arises from ties of hospitality is one which owes its origin to agreements, and which is carried on by means of letters between strangers. There is, therefore, natural friendship, and friendship between companions, and between strangers. Some also add a fourth kind, namely, the friendship of love.

XLVII. Of political constitutions there are five species. There is one kind which is democratical, a second which is aristocratical, a third is oligarchical, a fourth monarchical, and the fifth is tyrannical. Now, the democratical form of constitution exists in those cities in which the multitude has the chief power, and elects magistrates, and passes laws at its own pleasure. But an aristocracy is that form in which neither the rich, nor the poor, nor the most illustrious men of the city rule, but the most nobly born have the chief sway. And oligarchy is that constitution in which the magistracies are distributed according to some sort of rating: for the rich are fewer in number than the poor. The monarchical constitution is either dependent on law or on family. That in Carthage depends on law; that in Lacædemon and Macedonia on family; for they select their sovereign out of some particular family. But a tyranny is that kind of government in which the people are either cajoled or constrained into being governed by a single individual. Forms of government then, are divided into democracy, aristocracy, oligarchy, monarchy, and tyranny.

XLVIII. Again, of justice there are three species. For there is one kind which is conversant with the gods; a second which has reference to men; and a third, which concerns the dead. For they who sacrifice according to the laws, and who pay due respect to the temples, are manifestly pious to the gods. And those who repay what has been lent to them, and restore what has been deposited with them, act justly as to men. And those who pay due respect to the tombs, clearly are pious towards the dead. There is, therefore, one justice towards the Gods, a second towards men, and a third towards the dead.

XLIX. In the same way, there are also three species of knowledge. There is one kind which is practical, a second which is productive, a third which is theoretical. For the science of building houses or ships, is production. For one can see the work which is produced by it. Political science, and the science of playing the flute, or the harp, or such things as that, is practical; for one cannot see any visible result which has been produced by them, and yet they are doing something. For one man plays the flute or plays the harp, and another occupies himself with state affairs. Again, geometrical, and harmonic, and astronomical science are all theoretical, for they do nothing, and produce nothing. But the geometrician theorizes as to what relation lines bear to one another; and the harmonist speculates about sounds, and the astronomer about stars and about the world. Accordingly, of sciences some are theoretical, others productive, and a third species is practical.

L. Of medical science there are five species: one, pharmaceutical; a second, manual; a third, conversant about the regulation of the manner of life, and the diet; a fourth, the business of which is to detect diseases; and the fifth is remedial. The pharmaceutical relieves infirmities by means of medicines; the manual heals men by cutting and cauterizing; the one which attends to the diet, gets rid of diseases by altering and regulating the diet; the fourth produces its effects by a thorough comprehension of the nature of the disease; and the last relieves men from suffering by bringing prompt assistance at the moment. Medical science, then, is divided into the pharmaceutical, the manual, the dietetic, the diagnostic, and the remedial.

LI. Of law there are two divisions. For there is a written and an unwritten law. The one by which we regulate our constitutions in our cities, is the written law; that which arises from custom, is the unwritten law. As, for instance, for a man to come naked into the market place, or to wear woman’s clothes, are actions which are not prohibited by any law, and yet we never do them because they are forbidden by the unwritten law. Law, therefore, is divided into the written and the unwritten law.

LII. Discourse is divided into five heads; one of which heads is that which statesmen employ when they speak in the public assemblies; and this is called political. Another division is that which orators use in their written harangues, and bring forward for the sake of display in panegyrics or reproaches, or impeachments. And such a description of discourse as this is the rhetorical. A third class is that which private individuals use when conversing with one another. This is called private discourse. Another kind is that which is employed when men converse by means of putting short questions and giving brief answers to those who question them. This is called the dialectic kind of discourse. The fifth division is that which artists adopt when conversing on their own particular art, and this is called professional discourse. Thus discourse, then, is divided into political, rhetorical, private, dialectic, and professional.