Macroeconomists should be scientists seeking better explanations of the economic process of production and exchange.
By “scientific development” I mean development in mathematics or natural science. The scientific horizon recedes, expands when there occurs a crisis in existing methods, procedures, theories, assumptions which are seen to fail. They cannot handle known results, known observations or data, known conclusions. … Thus we have the triple revolution of Copernicus, Darwin, and Freud; the revolutions effected by Galileo, Newton, Einstein, quantum theory; the revolution in mathematics that began with analytic geometry and the calculus, went on to Riemannian geometry, and then to the developments in algebra due to Galois and to later developments In these cases there was a radical revision in concepts. (CWL 10, 92-3)
In the following passage, substitute “macroeconomists” for “scientists; and substitute “scientific macroeconomics” for “science.”
Now such a recession of the horizon within the scientific field meets with resistance. The subject dreads to change, to remodel the organization that is himself, his living in the scientific world. Max Planck, who made the fundamental discoveries connected with quantum theory (black-body radiation), asked in his autobiography what it is that puts a new scientific theory across. Is it the clarity of the observations or the exactness of the measurements or the coherence of the hypothesis or the rigor of the deduction or the decisiveness of the observational or experimental results? No, he said, it is none of these; they have nothing to do with it. Rather a new scientific theory gets across when the present generation of professors is retired. ¶ However, though there is a resistance within the field of mathematics and science, still, after a relatively brief lag the resistance is overcome universally and permanently. First it is overcome universally: a recession in the scientific horizon is not followed by a splintering into schools, where the schools endure indefinitely, where there are fruitless debates or such an impossibility of communication that there is no debate at all. A broadening of the scientific horizon becomes accepted by all the scientists. there is not a division of scientists into certain schools, after a certain lag. Secondly, that universal acceptance is also permanent: there is no tendency to revert to earlier positions; what has been achieved is retained, and a higher viewpoint is introduced that includes all that was had and adds to it; there is no going back. It is this property of scientific development that commands the great esteem in which science is held. Scientists will disagree; they will fight; the period of crisis and reformulation presents a spectacle of insecurity; but, usually within a relatively brief period of time, these problems are overcome, and when they are overcome, the achievement is universal and permanent (CWL 10, 93-4)
Much … the power of intelligence and reasonableness… is not exercised after the fashion of a steamroller that crushes opposition but through a mounting dialectical tension that makes absurdity ever more evidently absurd until man either rejects it or destroys himself by clinging to it. (CWL 3, 526/550)
Also see Why Macroeconomists Haven’t Yet Flocked to Functional Macroeconomic Dynamics and Lessons From I. Bernard Cohen’s Revolution in Science , Part 2: The Need for Brilliant Colleagues.