Noun
someone who maintains that any statement that cannot be verified empirically is meaningless
Source: WordNetTo get at the meaning of a statement the logical positivist asks, "What would the world be like if it were true?" The operationist asks, "What would we have to do to come to believe it?" For the pragmatist the question is, "What would we do if did believe it?" Abraham Kaplan
If you live today, you breath in nihilism ... it's the gas you breathe. If I hadn't had the Church to fight it with or to tell me the necessity of fighting it, I would be the stinkingest logical positivist you ever saw right now. Flannery O’Connor