In the debate over whether mathematical facts, properties, or entities explain physical events (in what philosophers call “extra-mathematical” explanations), Aidan Lyon’s (2012) affirmative answer stands out for its employment of the program explanation (PE) methodology of Frank Jackson and Philip Pettit (1990). Juha Saatsi (2012; 2016) objects, however, that Lyon’s examples from the indispensabilist literature are (i) unsuitable for PE, (ii) nominalizable into non-mathematical terms, and (iii) mysterious about the explanatory relation alleged to obtain between the PE’s mathematical explanantia and (...) physical explananda. In this paper, I propose a counterexample to Saatsi’s objections. My counterexample is Frank Jackson’s (1998a) program explanation for color experience, which I argue needs recasting as an extra-mathematical PE due to its implicit reliance on reflectance, a property that suffers conceptual regress unless redefined with Fourier harmonics. Pace Saatsi, I argue that this recast example is an authoritative PE, non-nominalizable, and minimally esoteric. Important for the indispensability debate at large, moreover, is that my counterexample reifies Fourier harmonics without the Enhanced Indispensability Argument (an argument to which Lyon applies PE as a premise). Indispensabilists have long overlooked the conditionalization of a limited mathematical realism on property realism, and my counterexample to Saatsi exploits this conditionalization. (shrink)

A de re objectual subject matter is a subject matter of the form how a1, a2 … are, whereas a de dicto objectual subject matter is a subject matter of the form how Fs are. An objectual subject matter is either a de re or de dicto objectual subject matter. This paper provides a systematic theory of aboutness towards objectual subject matters which, if correct, illuminates both the nature of intrinsicality and the general nature of aboutness. In addition to the (...) familiar distinction between partial and complete aboutness, I argue that there is a further orthogonal distinction between pervasive and hereditary aboutness, resulting in four ways in which a sentence, proposition or state of affairs can be about an objectual subject matter. I state and defend a number of basic principles concerning these varieties of aboutness as they apply to objectual subject matters and propose non-reductive analyses of them in terms of each other. I also propose an analysis of aboutness towards de re objectual subject matters in terms of aboutness towards de dicto objectual subject matters and put forward an attractive solution to a puzzle regarding aboutness due to Nelson Goodman. (shrink)