“We know: of course, with regard to the market and similar social structures, a great many facts which we cannot measure and on which indeed we have only some very imprecise and general information. And because the effects of these facts in any particular instance cannot be confirmed by quantitative evidence, they are simply disregarded by those sworn to admit only what they regard as scientific evidence: they thereupon happily proceed on the fiction that the factors which they can measure are the only ones that are relevant…On this standard there may thus well exist better ‘scientific’ evidence for a false theory, which will be accepted because it is more ‘scientific’, than for a valid explanation, which is rejected because there is no sufficient quantitative evidence for it…I prefer true but imperfect knowledge, even if it leaves much indetermined and unpredictable, to a pretence of exact knowledge that is likely to be false.”
-F.A. Hayek, “The Pretence of Knowledge.” Nobel Prize Lecture delivered on December 11, 1974.
* “Scientific evidence” in this context means data that are directly observable and measureable in “phenomena of unorganized complexity” as opposed to those of “organized complexity,” the latter being applicable to economics.
For the full argument please see http://www.nobelprize.org/nobel_prizes/economics/laureates/1974/hayek-lecture.html or contact me with questions and I will do my best to answer.