… is from page 295 of my late Nobel laureate colleague Jim Buchanan’s October 1991 article, co-authored with Viktor Vanberg (and originally published in Economics and Philosophy), “The Market as a Creative Process” as this article is reprinted in James M. Buchanan, Federalism, Liberty, and Law (2001), which is volume 18 of the Collected Works of James M. Buchanan (footnotes deleted; original emphasis):
The recognition that in human social affairs the future is undetermined but “created” in the process of choice, does not imply that the future is “beyond conjecture,” nor does it ignore that individuals have expectations about the future on which they base their action. The subjectivist’s understanding of the nature and role of such expectations is, however, critically different from their interpretation in a neoclassical [economics] framework. To the subjectivist, expectations may be more or less reasonable (in the sense of being more or less defendable in the light of past experience), but they can, ultimately, not be more than conjectures about an undetermined and, therefore, unknowable future. To the neoclassical economist, by contrast, expectations are about a future that is, in principle, knowable, even if its knowability may be limited by imperfections of the “expecters.” Ignorance of the future is essentially seen as a source of inefficiency, as a problem that can, in principle, be remedied by learning. By contrast, from a subjectivist position, such ignorance is simply “an inescapable characteristic of the human condition.”