Epistemology (; ) is a term first used by the Scottish philosopher James Frederick Ferrier to describe the branch of philosophy concerned with the nature and scope of knowledge; it is also referred to as "theory of knowledge". Put concisely, it is the study of knowledge and justified belief. It questions what knowledge is and how it can be acquired, and the extent to which knowledge pertinent to any given subject or entity can be acquired. Much of the debate in this field has focused on the philosophical analysis of the nature of knowledge and how it relates to connected notions such as truth, belief, and justification. The term was probably first introduced in Ferrier's Institutes of Metaphysic: The Theory of Knowing and Being (1854), p. 46.