James MacKaye

[J]ust as a boiler is required to utilize the potential energy of coal in the production of steam, so sentient beings are required to convert the potentiality of happiness resident in a given land area into actual happiness, and just as the engineer’s first care is to select a boiler having maximum efficiency of conversion, so the first care of Justice should be to populate the domain over which she has jurisdiction with beings capable of utilizing the available resources in the production of happiness, in a manner which will insure the maximum efficiency of conversion.

James MacKaye, The Economy of Happiness, Boston, 1906, p. 191