Søren Klausen

Abstract objects are widely held to pose a formidable epistemological challenge. It has seemed mysterious to many how we can have access to such strange and intangible entities. The article considers five influential ways to meet the challenge: Transcendental arguments, the indispensability argument, insisting that we just are able to grasp abstract objects and that no further explanation is needed, abstractionist accounts, and ontological reduction. None of these approaches is by itself sufficient or completely convincing, but together they make out a strong cumulative case for the accessibility of abstract objects.

Propositional attitudes are often classified as non-phenomenal mental states. I argue that there is no good reason for doing so. The unwillingness to view propositional attitudes as being essentially phenomenal stems from a biased notion of phenomenality, from not paying sufficient attention to the idioms in which propositional attitudes are usually reported, from overlooking the considerable degree to which different intentional modes can be said to be phenomenologically continuous, and from not considering the possibility that propositional attitudes may be transparent, just like sensations and emotions are commonly held to be: there may be no appropriate way of describing their phenomenal character apart from describing the properties and objects they represent.