John K. Whitaker writes as follows, in part. "... the analysis of economic phenomena became in the nineteenth century the arena in which were contested fundamental issues concerning the mind-body distinction and the validity of intuition as a source of knowledge additional to observation. For Jevons (in opposition to John Stuart Mill) only observation counted. ... Observational error was of course to be expected, so that underlying functional relations could be observed only probabilistically. Jevons did not imply that such an analogue represented absolute truth, but it was all that could be attained by scientific observation and reasoning. Such a methodological attitude pervaded his statistical analysis of economic time series. ..." (snip) I hold Prof. Whitaker in high regard, but respectfully call attention to Jevons' *Theory of Political Economy*, 5th Ed., Chap. VII, "Theory of Capital." Jevons begins with an Alexander Selkirk example, then says his views are "in fundamental agreement with those adopted by Ricardo;" - which they are. Few examples are given, and only after points are conceived a priori, and supported by citing previous theorists. I like Jevons' chapter, but not because it is either original or a posteriori. Rather, it is an alternative exposition of Ricardo, in some ways (but not all) clearer. Maas, of course, is the focused Jevons scholar. My impression, however, is that a generation or two of historians of thought have overstated Jevons' departure from his predecessors. Austrian economists, whom many lump with Jevons, refer routinely to part of their capital theory as "Ricardo Effect". Mason Gaffney