Different views of the nature of concepts lead to different views of the nature of cognition. They lead to different answers to the central question of epistemology: what is knowledge and how does man acquire it?
The objective approach to concepts leads to the view that, beyond the perceptual level, knowledge is the grasp of an object through an active, reality-based process chosen by the subject.
Concepts, like every other mode of cognition, must conform to the facts of reality. Human knowledge, therefore, is the grasp, not the creation, of an object. Beyond the perceptual level, however, such conformity can be attained only by …
Read the rest in Objectivism: The Philosophy of Ayn Rand.