The most valuable of all capital is that invested in human beings

I admit that these terms and the diagrams connected with them repel some readers, and fill others with the vain imagination that they have mastered difficult economics problems, when really they have done little more than learn the language in which parts of those problems can be expressed, and the machinery by which they can be handled. When the actual conditions of particular problems have not been studied, such knowledge is little better than a derrick for sinking oil-wells erected where there are no oil-bearing strata.

But if inventions have increased man's power over nature very much, then the real value of money is better measured for some purposes in labour than in commodities.

Knowledge is our most powerful engine of production.

Capital is that part of wealth which is devoted to obtaining further wealth.

The love for money is only one among many.

Material goods consist of useful material things, and of all rights to hold, or use, or derive benefits from material things, or to receive them at a future time.