No criticism can be brought against a branch of technical science from outside; no thought fitted out with the knowledge of a period and setting its course by definite historical aims could have anything to say to the specialist. Such thought and the critical, dialectical element it communicates to the process of cognition, thereby maintaining conscious connection between that process and historical life, do not exist for empiricism; nor do the associated categories, such as the distinction between essence and appearance, identity in change, and rationality of ends, indeed, the concept of man, of personality, even of society and class taken in the sense that presupposes specific viewpoints and directions of interest.

p. 145. - "The Latest Attack on Metaphysics" (1937)