Abstract
Chiffi and Pietarinen (2020) argue that the knowability paradox disappears if we adopt the concept of conjecturability instead of knowability within the framework of Peirce’s theory of science. They make two main claims: first, conjecturability plays an all-important role in scientific inquiry and it explains better scientific progress than knowability; second, conjecturability does not produce aparadox akin to the knowability paradox. However, based on our reading of Peirce, we contend that knowability plays an important role in scientific inquiry and progress. Moreover, we show that there is a conjecturability paradox with an analogous conclusion as the knowability paradox, which is rooted in their modal analysis of conjecturability.