Abstract: Truth is standardly considered a requirement on epistemic acceptability. But science and philosophy deploy models, idealizations and thought experiments that prescind from truth to achieve other cognitive ends. I argue that such felicitous falsehoods function as cognitively useful fictions. They are cognitively useful because they exemplify and afford epistemic access to features they share with the relevant facts. They are falsehoods in that they diverge from the facts. Nonetheless, they are true enough to serve their epistemic purposes. Theories that contain them have testable consequences, hence are factually defeasible.
Comment: In a context in which epistemology takes truth to be a necessary condition for knowledge and falsehood as an immediate knowledge defeater, this paper offers a new perspective on the epistemic value of falsehood as playing an important role both in science and in philosophy. In a nutshell, the author argues that although falsehoods diverge from the facts, they are "true enough" to serve their epistemic purpose. Some of the falsehoods employed both in science and philosophy result in models, idealisations and thought experiments: by sharing and exemplifying relevant features of the facts, they end up being cognitively useful. This could work as secondary literature for a postgraduate course in epistemology and philsoophy of science, insofar as it gives a new perspective on epistemic value falshood can play.