The thesis of this paper is that there are two styles of creativity, one a measured, problem-solvmg approach to the development of new knowledge, and the other, an emotional, and comparatively uncontrolled, free expression This duality has a long tradition, for example, the distinction made m the i8th Century between Enhghtenment (or Classicism) and Romanticism, in the 19th Century between Naturwissenschaft and Ceisteswissenschaft, and m the 20th between the "two cultures," scientific and hteraryIn his review of the psychological literature on thmkmg, Neisser (1963) mentions modem examples of similar dichotomies, such as McKellar's distinction (1957) between realistic and autistic thinking Neisser himself, usmg a computer model, refers to sequential and multiple processing the former is m close touch with the environment, uses mductive and deductive logic and is concerned with solvmg problems, the latter is largely nonconscious and erupts unconstrainedly from within Anderson (1968) has made an unusual speculative attempt to descnbe the two types of cogmtion m terms of the relative degree of dommance of hippocampal activity over reticular formation arousal that occurs m the problem-solvmg expert. Where there is hippocampal dommance, a person is likely to be mtroverted and to persevere with the scannmg of ideational associations m order to find the solution to a problem.Freud also distmguished between the two types of process when he differentiated between primary and secondary processes m The Interpretation, of Dreams. The former process, which is akin to "hot creativity," occurs largely out of reach of the reahty principle, although, as Kubie has pomted out (1958) it is more accurate to attnbute this type of creativity to the preconscious rather than the unconscious, smce it is partially m contact with and accessible to the conscious activity of the ego The primary processes involve the entertainment of unusual ideas, the neglect