… is from page 255 of my late Nobel-laureate colleague Jim Buchanan‘s 1966 paper “An Individualistic Theory of Political Process,” as this paper is reprinted in Moral Science and Moral Order (2001), Vol. 17 of The Collected Works of James M. Buchanan:
The whole problem of “politics and morals,” of “political obligation” arises out of attempts to get people to accept the “public interest” as their own. In other words, the reconciliation, if there is any, between private and public interests must come about through some moral force that the latter exerts on individual behavior. Political behavior of the individual becomes, in this familiar approach, necessarily moral behavior.
This whole conception of politics is foreign to [the individualistic theory of political process]. There exists no “social welfare function,” no “public interest,” as such in a society of freely choosing individuals, and there seems no reason to invent such a conception for analytical convenience.