It only remains that it should become universal. It long remains enclosed within the limits of the social group. All that contributes to the material and moral welfare of the group is good, and conversely; outside the group, all acts are _unmoral_. We find in history, and even at the present time, many proofs of this dualism or duplication of the individual, according as he is acting within his own social environment or with regard to strangers. Such were the Germans of Cæsar’s time.[183] In their earlier period, the Greeks considered themselves as less under moral obligation towards the Barbarians, and the Romans towards foreigners (_hostes_). It is especially owing to the efforts of the philosophers—Socrates, Plato, Aristotle, the Stoics—that justice ceased to be national and became universal. It might be added that at that period when the notion of justice remains a national one, it still varies within the group, according to caste; it is not the same for priests and warriors, for free men and for slaves, for aristocrats and for merchants. In the beginning, particularism was the rule. ----- Footnote 183: “Latrocinia nullam habent infamiam quæ extra fines cujusque _civitatis_ fiunt.”—_De Bell. Gall._, vi. 21. ----- It is evident that, on the negative side, the evolution of moral life has been especially due to the progress of intelligence; the emotional element has only been incidental. Compared with the sense of justice, the feeling of active benevolence, if not evolved more quickly, at least appeared sooner, because nearer to instinct and less dependent on reason. A certain philosopher (Kant, I believe) was surprised that there is so much kindness and so little justice among men. He did not observe as a psychologist, or else he was led astray by intellectualist prejudice. This must be so, because tenderness is innate and spontaneous, justice acquired and deliberate; because one springs directly from an instinct, while the other has to undergo various metamorphoses. If man is sociable and moral, it is less because he thinks than because he feels in a certain manner and tends in a certain direction.