ABSTRACT
This chapter considers several general versions of the conceivability criterion of possibility as well as versions of its major competitor — the formal or describability criterion of possibility. In examining George Berkeley’s criteria of possibility and impossibility, it addresses two distinct but related questions. First, there is the question of the metaphysical criterion of possibility, that is, what characteristic distinguishes possible objects from impossible objects? Second, there is the question of the epistemological criterion of possibility, that is what grounds will justify one’s claim to know that a certain kind of object is possible? The chapter examines Berkeley’s distinction between possible and real objects. It explores the question of Berkeley’s metaphysical criteria and epistemological criteria of possibility and impossibility. Berkeley presents what might be called the volitional criterion, namely, ideas of the imagination are dependent on one’s own will, while ideas of the senses are independent of one’s own will.
