Knowledge is not simply another commodity. On the contrary. Knowledge is never used up. It increases by diffusion and grows by dispersion.

Boorstin contrasts knowledge with ordinary goods: material commodities are depleted by consumption and rivalrous in use, while knowledge is non-rivalrous—sharing it does not diminish it. In fact, dissemination can amplify its value by enabling others to test, refine, combine, and apply ideas in new contexts. The line also implies a civic and institutional ethic: libraries, universities, free inquiry, and open communication are engines of growth because they multiply understanding through circulation. The quote thus functions as an argument for education and the broad distribution of information, suggesting that societies prosper when they treat knowledge as a public good rather than a scarce possession to be hoarded.