Cassirer's goal is to comprehend the specialized structures of different forms of knowledge, relate them to one another as a whole, and through this to identify the basic formative principle which is exemplified in them all. Cassirer follows Hegel in arguing that this unification must address the way forms of knowledge develop through their own internal logical and historical progression, and through their relations to one another. The basic symbolic function involves recognizing a particular as representative of a greater whole. This basic structure is embodied in different ways under different circumstances. Presumably there are different varieties of symbolic form because the basic categorial framework, of space, time, causality, thing, number and magnitude, operates with different emphases in different contexts of existence. Cassirer's task is, accordingly, to develop this basic strategy even further, and to explain the logical structure and historical development of different symbolic forms and the formative principle that underlies them.