the world fills the greater part of consciousness. As the formation of an ‘I,’ of an individuality clearly conscious of its separate existence, is the highest achievement of living matter, so the highest degree of development of the ‘I’ consists in embodying in itself the ‘not-I,’ in comprehending the world, in conquering egoism, and in establishing close relations with other beings, things and phenomena. Auguste Comte, and after him Herbert Spencer, have named this stage ‘altruism,’ from the Italian word _altrui_, ‘others.’ The sexual instinct which forces an individual to seek for another individual is as little altruism as the hunger which incites the hunter to follow an animal in order to kill and eat it. There can be no question of altruism until an individual concerns himself about another being from sympathy or curiosity, and not in order to satisfy an immediate, pressing necessity of his body, the momentary hunger of some organ. Not till he attains to altruism is man in a condition to maintain himself in society and in nature. To be a social being, man must feel with his fellow-creatures, and show himself sensitive to their opinion about him. Both the one and the other presuppose that he is capable of so vividly representing to himself the feelings of his fellow-creatures as to experience them himself. He who is not capable of imagining the pain of another with sufficient clearness to suffer the same himself will not have compassion, and he who cannot exactly feel for himself what impression an action or an omission on his part will make on another will have no regard for others. In both cases he will soon see himself excluded from the human community as the enemy of all, and treated as such by all, and very probably he will perish. And to defend himself against destructive natural forces and turn them to his advantage, man must know them intimately--that is, he must be able distinctly to picture their effects. A clear presentation of the feelings of others, and of the effects of natural forces, presupposes the faculty of occupying himself intensively with the ‘not-I.’ While a man is attending to the ‘not-I,’ he is not thinking of his ‘Ego,’ and the latter descends below the level of consciousness. In order that the ‘not-I’ should in this way prevail over the ‘I,’ the sensory nerves must properly conduct the external impressions, the cerebral centres of perception must be sensitive to the excitations of the sensory nerves, the highest centres must develop, in a sure, rapid and vigorous manner, the perceptions into ideas, unite these into conceptions and judgments, and, on occasion, transform them into acts of volition and motor impulses. And as the greatest part of these different activities is accomplished by the gray cortex of the frontal lobes, this means that this gray cortex must be well developed and work vigorously.