If a man were living in isolation his income would be literally his product. Make him the monarch and owner of an island, and the fruits that he raises and the clothing that he makes constitute, in themselves, his income. This ceases to be true when trading begins.

In the brief preface is expressed the hope that 'it may be found that these principles settle questions of agrarian socialism. … Though the process was savage the outlook which it afforded was not wholly evil.

John Bates Clark (January 26 1847 – March 21 1938) was an American neoclassical economist.