The hostility depends, not upon the existence of such advantageous discriminations for a time, but upon their persistence for too long a time.

When, either from natural or artificial causes, they are properly selected, they contribute at the time of their selection both to individual and to social efficiency.

They have been earned, and it is both just and edifying that, in so far as they have been earned, they should be freely enjoyed.

On the other hand, they should not, so far as possible, be allowed to outlast their own utility.

They must continue to be earned.