In the last chapter, I attempted to show how the economic process in any complex society takes its toll in terms of the individual agent's autonomy or ‘freedom to do’. There is some scope for choice as regards the co–ordination system adopted and whether to economize or not on the use of conduct–enforcing mechanisms. Changes in the rules of the economic game may be thought worth having, so as to try to rule out the occurrence of certain undesirable outcomes. But in any case there will be large areas of behaviour in economic life which lie outside the sphere of ‘ideas’. In these areas, the agent's beliefs and opinions turn out to be of little or no significance in so far as his outward, observable conduct in the system is concerned.

In this chapter, I shall draw attention to the existence of powerful internal or psychological constraints on the autonomy of the individual agent. Drawing on the philosophy of action put forward by Hume and Adam Smith, I will suggest that agents act on the basis of what they believe is in their own interest, but that this opinion of interest is largely the work of their sub–rational (meaning non–rational rather than irrational) dispositions and motivations. An important step in this argument will be the attempt to elucidate the eighteenth–century concept of passion.