he change for the un- derlying philosophy and logic of science is, however, very great. In relation to the metaphysics of the Newtonian system it is hardly less than revolutionary. What is known is seen to be aproduct in which the act of observation plays aneces- sary role. Knowing is seen to be aparticipant in what is finally known. Moreover, the metaphysics of existence as something fixed and therefore capable of literally exact mathematical description and prediction is undermined. Knowing is, for philosophical theory, acase of specially directed activity in- stead of something isolated from practice. The quest for cer- tainty by means of exact possession in mind of immutable reality is exchanged for search for security by means of active control of the changing course of events. Intelligence in op- eration, another name for method, becomes the thing most worth winning.