Epistemology and Ontology in Frege and Peirce: On Thoughts and Generals*

Abstract

The main aim of this paper is to compare the refl ections by Frege and Peirce with respect to the ontology and epistemology of some abstract entities or abstract elements, namely, Fregean thoughts and Peircean generals. The reason for this comparison is that they have given distinct answers to similar epistemological and ontological problems. Therefore, the paper will concentrate basically on the importance given by them to abstract entities or abstract features, and on the ontological position they have taken in regards to them, and which were motivated by their interests in science and in the justifi cation of scientifi c knowledge. The paper will also analyse the different roles that language and representation systems play in Frege’s and Peirce’s refl ections with respect to these abstract elements or entities,  favouring Peirce’s position, which did not separate ontology from epistemology, and, therefore, it is not committed to the Platonism Frege was led to.