As a school of thought, positivism is best defined as select one: a. the notion that the afterlife will be either pure torment or pure bliss depending upon one's conduct during earthly existence. b. all choices listed are the best definitions of positivism c. the notion that religious and metaphysical modes of knowing are imperfect and that knowledge must be based on what can be directly observed in nature and human activity. d. a philosophy based on the teachings of the ancient greeks that emphasizes the use of logic to solve complex questions. e. a philosophy focusing on human values and emphasizing the use of optimistic reasoning.