Book excerpt: Pieranna Garavaso and Nicla Vassallo investigate Gottlob Frege's notion of thinking (das Denken) to provide a new analysis of a largely unexplored area of the philosopher's work. Confronting Frege's deeply seated and widely emphasized anti-psychologism, Frege on Thinking and Its Epistemic Significance claims that the objective human science that Frege proposed can only be possible through a nuanced notion of thinking as neither merely psychological nor merely logical. Focusing on what Frege says about thinking in many passages from his works, Garavaso and Vassallo argue that Frege was engaged with issues that are still alive in contemporary debates, such as the definition of knowledge and the necessary role of language in conceptual thinking and in the expression of thoughts. Frege on Thinking and Its Epistemic Significance is essential not only for those interested in a new and original reading of Frege’s philosophy, but also for anyone engaged in epistemology, logic, psychology, philosophy of language, and the history of analytic philosophy.