[245] If man looks at his world---and we can see this in the earliest beginnings of the scientific consciousness, namely in the pre-Socratic analysis of reality---he discovers in his world different levels of being and different categories in which he grasps being. In these different levels, and their corresponding categories, he tries to find a basic level. In the Ionian philosophy of nature, this basic level was matter, and came to its fulfillment in the atomistic analysis of the material world in Leucippus^a and Democritus^b---later on, in the Epicureans.^c Or he finds the fundamental level in the form, in the mathematical structure of reality. This was first done in the Pythagoreans^d when they said that the essence of reality is number. And it has been repeated in modern physics, where mathematical equations have replaced the concept of matter. Or there is a third possibility: one does not start with either matter or form, but with quality, and structure, and believes that the fundamental level of reality is the qualities or essences of things--- what I called potentialities (in answer to the question) which BECOME actualized, with the help of matter and mathematical form. This is the Platonic ^eanswer. There are other possible answers---the Neoplatonic^f, in which it is the spiritual life as we experience it in ourselves which is the essence of reality. Now however this may be, man, in encountering his world, distinguishes these levels and their categories. He distinguishes also levels of developed beings: the inorganic level, the organic, the psychological, the spiritual, the level of history. All these levels he sees beside each