… is from page 21 of Hayek’s The Trend of Economic Thinking  (Vol. 3 of Hayek’s Collected Works); the quotation comes from the 1933 essay after which this volume is named; in the following passage Hayek is discussing the negative reaction by many people in the 19th century to economics:
The attack on economics sprang rather from a dislike of the application of scientific methods to the investigation of social problems. The existence of a body of reasoning which prevented people from following their first impulsive reactions, and which compelled them to balance indirect effects, which could be seen only by exercising the intellect, against intense feeling caused by the direct observation of concrete suffering, then as now, occasioned intense resentment.
No small part of Keynes’s (and the Keynesians’s) success is due, I believe, to their dressing up in scientific jargon and garb what are, at bottom, little more than ad hoc excuses for people to follow “their first impulsive reactions.” Keynesians’s pose as scientists – their substitution of scientism for science – masks their rejection of a genuinely scientific approach to the study of the economy.