Maybe we ought to have a world in which things are divided between people kind of fairly.

The simplest scheme of evolution is one that depends on two processes; a generator and a test. The task of the generator is to produce variety, new forms that have not existed previously, whereas the task of the test is to cull out the newly generated forms so that only those that are well fitted to the environment will survive.

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

Learning results from what the student does and thinks, and only from what the student does and thinks. The teacher can advance learning only by influencing the student to learn.

Mathematics is a language. We want scientists to be able to read it, speak it, and write it. But we are are not training them to be grammarians.

The aim ... is to provide a clear and rigorous basis for determining when a causal ordering can be said to hold between two variables or groups of variables in a model . . . . The concepts refer to a model-a system of equations-and not to the 'real' world the model purports to describe.

Human beings, viewed as behaving systems, are quite simple. The apparent complexity of our behavior over time is largely a reflection of the complexity of the environment in which we find ourselves.