  Natural science is divided by Bacon into physics and metaphysics. The former investigates variable and particular causes, the latter reflects on general and constant ones, for which the term form is used. Forms are more general than the four Aristotelian causes and that is why Bacon's discussion of the forms of substances as the most general properties of matter is the last step for the human mind when investigating nature. Metaphysics is distinct from philosophia prima. The latter marks the position in the system where general categories of a general theory of science are treated as (1) universal categories of thought, (2) relevant for all disciplines. Final causes are discredited, since they lead to difficulties in science and tempt us to amalgamate theological and teleological points of doctrine. At the summit of Bacon's pyramid of knowledge are the laws of nature (the most general principles). At its base the pyramid starts with observations, moves on to invariant relations and then to more inclusive correlations until it reaches the stage of forms. The process of generalization ascends from natural history via physics towards metaphysics, whereas accidental correlations and relations are eliminated by the method of exclusion. It must be emphasized that metaphysics has a special meaning for Bacon. This concept (1) excludes the infinity of individual experience by generalization with a teleological focus and (2) opens our mind to generate more possibilities for the efficient application of general laws.