Like consistency, instrumental rationality is sometimes seen as an a priori constraint
so that it seems as unintelligible to ask 'T am thirsty but why should I drink?" as to
exclaim "I should drink and not drink" (taking inconsistent attitudes at any one time).
If you are thirsty and it is within your means to relieve your longing, you are, ceteris
paribus, normatively compelled to do so. What is the force o f this idea?
Under the standard theory o f choice underlying much o f recent economics and
the social sciences, people are supposed to be rational in that their preferences form an
ordering such that they always do what they most prefer. The theory attaches so-
called expected utilities to consequences o f actions, so that people can be seen as
' Under "contractualistic" I understand the tradition that m odels and perhaps ju stifies norm ative demands as the outcome o f decisions under the constraints o f instrumental rationality from our actual aims, desires or purposes. This is true o f Hobbes, but neither o f Locke, Rousseau or Kant. They defend for various reasons a h ypoth etical social contract, and stand in direct line to a prominent recent theory: Rawls' T heory o f Ju stice. For "contractarians" (as I call this latter breed) the question is not i f w e actually have instrumental reasons to submit to given norms, rather a normative system is qualified as having been instrumentally chosen in a hypothetical situation. The characterization o f the hypothetical choosing situation determines which set o f norms it is rational to choose. Such an "Original Situation" therefore m erely reflects the norms the choosers already have, the choosing situation itself is not the outcom e o f instrumental deliberation. Honderich rightly critisizes Raw ls' contractarian label as m isleading. The support the hypothetical contract gives to a normative system is the support o f an "Ordinary Argument" (Honderich, 1975, 70) not o f instrumental thinking. It brings m erely into the open principles w e already have - or may acquire on reflection.
R aw ls m ight even agree with this description: "According to the provisional aim o f moral philosophy, one might say that justice as fairness is the hypothesis that the principles w hich w ould be chosen in the original position are identical with those that match our considered judgm ents, and so these principles describe our sense o f justice... When a person is presented with an intuitively appealing account o f his sense o f justice ... he may w ell revise his judgm ents to conform to its principles even though the theory does not fit his existing judgments exactly." (Rawls, 1971, 48)
Within m y framework, Rawls' enterprise stands som ehow between theories placing em phasis on basic intuitions m ost people share (e.g. W iggins, M cD ow ell, Blackburn; Ch. 4 .1 ) and Hare's rigid consistency constraints (Ch. 4.2).
adopting what constitutes the best means to satisfy their preferences. This is an
explanatory claim. People's behaviour is interpreted under a constraint o f instrumental rationality which reveals their preferences. I f you reach for a glass o f water and not a
piece o f bread you are taken to be thirsty, having adopted the means to m axim ize
expected utility. No gap remains between preference and choice. It is not that you
chose the glass o f water because you had a preference for doing so. W e cannot ask
why a preference should be satisfied. A gap between preference and choice may only
appear if you count as irrational, i.e. if no maximizing interpretation can be given to
your actions. For example, you may insist that you preferred the bread though you
chose the water. To admit widespread irrationality o f that kind, however, is bad news
for the explanatory claims o f the theory o f choice itself since it would fail to describe
behaviour it set out to describe. In so far as you are party to the interactions o f the
socio-economic world you have, as interpreted subject, no authority about what your
preferences are. You prefer what you choose. Thus the question does not arise what
you ought to choose, and whether you have indeed adopted the best means to satisfy
your preference. The only normative element is interpretation under the constraint o f
maximization. ’
In the greater number o f so-called parametric cases, i.e. situations o f choice in
which a person takes her actions to be the sole variable in a fixed environment, the
theory o f choice appears to describe and predict socio-economic behaviour quite
successfully.2 In situations o f strategic choice, however, where the outcome o f one's
actions depends on the actions o f one or more other persons, the theory runs into a
This abstract o f rather familiar ideas about instrumental rationality derives from R am sey and his axiom s about preference ordering and subjective probability (1931). Pareto (1972 (1 9 2 7 )) pioneered the use o f so-called utility in dices as m athem atical representations o f the total o f an agent's m otivations; under the interpretative constraints o f instrumental rationality exp ected u tilities are attached to consequences o f actions. The theory o f choice was canonisized in Savage's four axiom s (1 9 7 2 (1 9 5 4 )).
^ Even for decisions in fixed enviroments, puzzles arise. In a Russian roulette case, the removal o f one o f four bullets in a six-cham ber-revolver reduces the probability o f k illing y o u rse lf m ore than the removal o f only one remaining bullet, yet m ost people would be prepared to pay m ore for the rem oval o f the last bullet, thus violating Savage's axioms. (Cf. Kahneman & Tversky, 1979)
number o f deeper troubles. Most prominently, it struggles to explain basic cases o f
reciprocity. The behaviour o f cooperating parties often resists an interpretation under
the maximizing constraint as adopting the best means to given preferences.