Conflict may be defined as a situation of competition in which the parties are aware of the incompatibility of potential future positions, and in which each party wishes to occupy a position that is incompatible with the wishes of the other.

Economics, we learn in the history of thought, only became a science by escaping from the casuistry and moralizing of medieval thought.

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.

Production functions involving only land, labor and capital... never work and never explain economic development.

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

One advantage of exhibiting a hierarchy of systems in this way is that it gives us some idea of the present gaps in both theoretical and empirical knowledge. Adequate theoretical models extend up to about the fourth level, and not much beyond. Empirical knowledge is deficient at practically all levels.

[The integrative system] deals with such matters as respect, legitimacy, community, friendship, affection, love, and of course their opposites, across a broad scale of human relationships and interactions.