Those predispositions in man which serve the use of his reason are therefore destined to be fully developed.

This destiny, however, cannot be realised in the individual; it can only be realised in the species.

For reason works tentatively, by progress and regress.

Each man would require an inordinate length of time to make a perfect use of his natural tendencies.

Therefore, as life is short, an incalculable series of generations is needed.
The means which nature employs to develop these tendencies is the antagonism which in man's social state exists between his gregarious and his antigregarious tendencies.