Restructuring the Sciences

Following Auguste Comte’s publication of Philosophie Positive and prior to World War I, it was virtually incumbent on anyone writing a book on logic to include a classification of the sciences.  For example, Alexander Bain, William Whewell, and Herbert Spencer all have detailed accounts of how the sciences should be classified.  As a logician, Charles Sanders Peirce was not exempt from this desideratum.

This essay explains how Peirce’s classification of the sciences developed between 1902 and 1903 and provides a justification for the 1903 classification, which Peirce continued to endorse for the remainder of his life.  Peirce’s 1902 classification draws its inspiration from classification in the biological sciences, especially the work of Peirce’s mentor Louis Agassiz.  In contrast, Peirce’s 1903 classification draws its inspiration from his own mathematically-derived categories of Firstness, Secondess, and Thirdness (for more on these categories, see 2010a and 2012b; for more on their mathematical derivation, see 2014b).

Also in this essay are: (a) a brief discussion of the three categories; (b) a brief account of how Peirce distinguishes among logic, formal logic, and pure mathematics; (c) comments on the relation of Peirce’s classification of the sciences to Kant’s conception of an architectonic; (d) a defense of Murray Murphey’s assumption that Peirce held an architectonic view of the sciences from the start of his philosophical career; and (e) a brief defense of the importance of classifying the sciences.