The social sciences, I thought, needed the same kind of rigor and the same mathematical underpinnings that had made the 'hard' sciences so brilliantly successful.

Learning is any change in a system that produces a more or less permanent change in its capacity for adapting to its environment.

Assuming that a tax increase is necessary, it is clearly preferable to impose the additional cost on land by increasing the land tax, rather than to increase the wage tax - the two alternatives open to the City (of Pittsburgh). It is the use and occupancy of property that creates the need for the municipal services that appear as the largest item in the budget - fire and police protection, waste removal, and public works. The average increase in tax bills of city residents will be about twice as great with wage tax increase than with a land tax increase.

Solving a problem simply means representing it so as to make the solution transparent.

All behavior involves conscious or unconscious selection of particular actions out of all those which are physically possible to the actor and to those persons over whom he exercises influence and authority.

I don't care how big and fast computers are, they're not as big and fast as the world.

The world is vast, beautiful, and fascinating, even awe-inspiring - but impersonal. It demands nothing of me, and allows me to demand nothing of it.