Abstract
The author--a Danish philosopher influenced by Moore, the later Wittgenstein, and C. I. Lewis--lays bare three fundamental rules of "informal logic" implicit in any description of empirical reality. They are: psychological expressions cannot be applied independently of the personal pronouns, personal pronouns cannot be applied independently of names of ordinary things, and names of ordinary things cannot be applied independently of words expressing possibility of action. A number of important consequences are drawn: in particular, that certain traditional philosophical problems--such as the existence of the external world and the future validity of physical laws--cannot be properly formulated; and that the description of nature cannot afford any argument for psychological determinism. A stimulating book. --T. L. M.