A trick to using malapropism is to ensure that the two words (the original and the substitute) sound similar enough for the reader to catch onto the intended switch and find humor in the result.
Positivism is a philosophical theory stating that positive knowledge is based on natural phenomena and their properties and relations. Thus, information derived from sensory experience, interpreted through reason and logic, forms the exclusive source of all authoritative knowledge.
A brief history of positivism also is provided, tracing the development and use of the biological theories from early (largely discredited) beliefs, to the most current theories on the relationship of biology to behavior.