 Blaug’s and Hutchison’s criticisms have sometimes been challenged on the grounds that economic theories cannot be tested, because of their ceteris paribus clauses and the many subsidiary assumptions required to derive testable implications (Caldwell 1984). But this response ignores Popper’s insistence that testing requires methodological decisions not to attribute failures of predictions to mistakes in subsidiary assumptions or to “interferences.” For views of Popper’s philosophy and its applicability to economics, see de Marchi (1988), Caldwell (1991), Boland (1982, 1989, 1992, 1997), and Boylan and O’Gorman (2007), Backhouse (2009), and Thomas (2017).