As far as many statistical series that are related to activities of mankind are concerned, the date that divides human history into two equal parts is well within living memory. The world of today is as different from the world I was born in as that world was from Julius Caesar s. I was born in the middle of human history, to date, roughly. Almost as much has happened since I was born as happened before.

Even personal tastes are learned, in the matrix of a culture or a subculture in which we grow up, by very much the same kind of process by which we learn our common values. Purely personal tastes, indeed, can only survive in a culture which tolerates them, that is, which has a common value that private tastes of certain kinds should be allowed.

At the opposite pole from the gift is tribute - that is, a grant made out of fear and under threat. A threat is a statement of the form "you do something that I want or I will do something that you do not want.

It [knowledge] is clearly related to information, which we can now measure; and an economist especially is tempted to regard knowledge as a kind of capital structure, corresponding to information as an income flow. Knowledge, that is to say, is some kind of improbable structure or stock made up essentially of patterns - that is, improbable arrangements, and the more improbable the arrangements, we might suppose, the more knowledge there is.

In calling society an ecological system we are not merely using an analogy; society is an example of the general concept of an "ecosystem" that is, an ecological system of which biological systems - forests, fields, swamps - are other examples.

The controversy as to whether socialism is possible has been settled by the fact that it exists, and it is a fundamental axiom of my philosophy, at any rate, that anything that exists, is possible.

The use of isoquants to describe the production function did not develop to any great extent until the thirties.