It is clear that the building of models is not a purely mechanical process but requires skill of a high order - not merely mathematical skill but a sensitivity to the relative importance of different factors and a critical, almost an artistic, faculty in the selection of behaviour equations which are reasonable, tentative hypotheses in explaining the behaviour of actual economies.

[Even the mechanism can be endowed with an image. Thus] the thermostat has an image of the outside world in the shape of information regarding its temperature. It has also a value system in the sense of the ideal temperature at which it is set. Its behavior is directed towards the receipt of information which will bring its image and its value systems together.

One of the most important skills of the economist, therefore, is that of simplification of the model. Two important methods of simplification have been developed by economists. One is the method of partial equilibrium analysis (or microeconomics), generally associated with the name of Alfred Marshall and the other is the method of aggregation (or macro-economics), associated with the name of John Maynard Keynes.

Thus we seem to be on the verge of an expansion of welfare economics into something like a social science of ethics and politics: what was intended to be a mere porch to ethics is either the whole house or nothing at all. In so laying down its life welfare economics may be able to contribute some of its insights and analytical methods to a much broader evaluative analysis of the whole social process.

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.

Canada has no cultural unity, no linguistic unity, no religious unity, no economic unity, no geographic unity. All it has is unity.

The trouble with taxonomic boxes is... that that they tend to be empty, however beautiful they are on the outside.