Peirce on the Primal Positive Science

In his classification of the sciences, Charles S. Peirce gave precedence to phenomenology over all other positive sciences, including logic and semiotic, the two for which he is best known. This implies that logic depends on phenomenology for some basic principles, just as the more “special” sciences depend on logic to guide their investigations. Yet many of Peirce’s definitions of phenomenology (and phaneroscopy, as he called it later), and examples that he gives of investigations of that type, show that some kind of mathematical logic is involved in phenomenology itself, as part of a method which discerns the “categories” or “elements” ubiquitous in all phenomena. This paper brings together a large number of Peirce texts, written both before and after he began referring to this “science” as “phenomenology,” to elucidate the complexity of its relations with other sciences, and to show how its unique methods justify Peirce’s reference to it as “the most primal of all the positive sciences.”