The article presents an analysis on whether or not philosopher Charles Sanders Peirce considered the possibility that philosopher Benedictus Spinoza's metaphysics includes ontological Firstness. It examines the book by Peirce's "Lectures on Pragmatism" wherein he repeatedly identifies Spinoza with the cosmological model that embraces the "Firsts," "Seconds," and "Thirds" categories. It examines the kind of pragmaticist Peirce thought Spinoza was and determines the greatest obstacle regarding the latter as a pragmaticist to be his his purported necessitarianism.