D. M. MACKAY 
ineradicably instrumental character of public scientific enquiry 
here is to lay emphasis on a new dimension of the responsibility 
of the scientist, at present barely acknowledged. It is not simply 
that we are able to alter people’s opinions predictably, which 
all propagandists can. What seems objectionable is our 
unrecognized and unavoidable power to do so when we are 
asked (and believed) to supply only “objective”? information. 
Any situation that can give one man an effective voting power 
of thousands, without being held proportionately responsible, 
needs watching. If, as scientists, we feel it to be an undemocratic 
one, the remedy lies largely in our own hands. 
Thirdly, this of course presses upon us the question suggested 
earlier. Who, in all our discussion of the matter, are ““we’’? 
We here assembled are scientists; but without intolerable 
hubris we cannot divorce ourselves from the very society about 
which we have been speaking—whose ills we would like to 
remedy. What differentiates us is not any special competence 
to decide that society should pursue one goal rather than 
another, but only a certain skill in calculating what may 
happen if it does. 
Here we face a current growing point in our understanding 
of social phenomena. What can justifiably be believed by a 
group (in the first person plural) must obviously be related to 
what can justifiably be said by each of its members (in the first 
person singular). Yet as Michael Foster pointed out in the 
symposium? Faith and Logic, the logic of this relation (between 
talk of “I”? and talk of ‘‘We?’’) is still surprisingly little under- 
stood. Our present discussion has uncovered only one of its 
peculiarities, but it is sufficient to show the need for fresh and 
urgent thought on the special limitations of the scientific 
method and of the scientist when functioning as a guide to the 
evolution of social attitudes. 
It is equally important, on the other hand, not to exaggerate 
these limitations; for great benefits, as we have seen, may be 
expected to accrue from a better understanding of the social 
mechanism. To establish that scientific investigation can only 
illuminate, and not replace, human valuation and commitment, 
166 
