Philosophy Self-Study 2026, 03 (Epistemology, Ernest Sosa)

The third chapter further works on the issue regarding the use of the cogito to escape the radical skepticist framework. It recognizes the infinite regression problem that radical skepticism opens when trying to lay the groundwork for an epistemic chain of revelations. It rings true, but also acknowledges the fact that every attempt trying to emerge from it will be tautological somehow. "Bootstrapping" he calls it. That also makes all attempts of this somewhat futile, and the radical skeptic approach akin to defeatism. Instead, perception is the only actual base from which epistemological insight can emerge from, but only if vetted properly. For this, Sosa introduces sensitive and insensitive perception. The latter is made up of perceptions that leave include some inference that goes unverified.

From these emerge the idea of "justified true belief" (JTB in the text), which can be further subdivided into the way one arrives at them. Some of which, when derived by way of Gettier cases (a kind of epistemic problem defined initially by Edmund Gettier) can be either chosen as especially sound, or as lacking. The fourth chapter uses the modal, explanatory and constitutional JTBs as ways to arrive at more material methods of checking epistemic content, which is the concept of aptness, a measure by which knowledge is applicable, independently of the circumstances in which the subject is in. It sets the bar for full knowledge high, but tangible, given the expectations are reasonable. The various levels of JTB can be picked apart further, depending on how one arrives at it, and under what circumstances they were determined. It's granularity is partially about whether the epistemic uncertainty is due to plausible factors that can't be easily verified (such as the various simulation theories) or whether the process of proof is "proportionate" to the effort it would take someone to conduct it.

Moving on, the value of knowledge is briefly expressed through its relation to human mechanisms. Sosa argues that curiosity could only be fully sated by knowledge, and that one of the aspects of knowledge: "rational intent" (he calls it "adroitness") is what sets the human value of knowledge apart from those forms of non-rational actors. This is the lead-up to the whole virtue-epistemology thing that he has helped develop. I suppose people familiar with the field of epistemology might as well start in chapter 9, where Sosa begins putting virtue and epistemics into context with one another. He has argued them as linked through the intentionality of demonstrating knowledge, in order to tell it apart from JTB, but he also presents that either personal virtues can facilitate epistemology, or that epistemology uses personal virtue as a category in itself.

As might be expected for a moral philosopher, Sosa believes that knowledge infers responsibility upon the acting individual, and not only does it infer a virtuous quality, it also gives rise to several emergent behaviors that the reader might be familiar. With knowledge of sufficient knowledge comes "judgement" for example, which can only be passed as a consequence of an informed or uninformed action. It is then more important to Sosa whether knowledge is acted upon virtuously, than whether knowledge was obtained. Sometimes the process of acquiring knowledge requires encroaching on morals so far that the acquisition could be fully said to be in violation of informed action. Like many other philosophers of his time, Sosa also values action more than he does inaction, though I can think of few scenarios in which moral action and inaction are directly in contention. The trolley problem, perhaps if the path of inaction is taken "in bad faith", though I do wonder how Sosa would categorize for example a desperate attempt of cramming for an exam one knows one will definitely fail despite the effort. Because the responsiblist component values primarily the outcome as a result of action, I find the field of strategic inaction somewhat unexplored.