In Introduction to Objectivist Epistemology Ayn Rand presents her revolutionary theory of concepts. In the Foreword she indicates that, in essence, there have been four schools of thought on the issue: extreme realism, moderate realism, nominalism, and conceptualism. To appreciate fully the brilliance of Ayn Randís theory, one must know what these four schools of thought maintained, and why. In this course we will examine the exact views and errors of the four schools. We will begin by considering how the problem of concepts arose in philosophy and then move to the arguments of the major thinkers on the issue, from Platoís time to the 20th century. In the process we will see why realism led to intrinsicism, and nominalism and conceptualism to subjectivism and, therefore, why the issue of concepts is, as Ayn Rand identified it, philosophyís central issue. The course will conclude by contrasting Ayn Randís theory to these four, thereby allowing us to grasp fully its significance and place in the history of philosophy.