 Departing even more radically from the norm in philosophy, a few philosophers (e.g., Michael Martin 1990: 463–464) join many non-philosophers in defining “atheist” as someone who lacks the belief that God exists.  This commits them to adopting the psychological sense of “atheism” discussed above, according to which “atheism” should not be defined as a proposition at all, even if theism is a proposition. Instead, “atheism”, according to these philosophers, should be defined as a psychological state: the state of not believing in the existence of God (or gods). This view was famously proposed by the philosopher Antony Flew and arguably played a role in his (1972) defense of an alleged presumption of “atheism”. The editors of the Oxford Handbook of Atheism (Bullivant &amp; Ruse 2013) also favor this definition and one of them, Stephen Bullivant (2013), defends it on grounds of scholarly utility. His argument is that this definition can best serve as an umbrella term for a wide variety of positions that have been identified with atheism. Scholars can then use adjectives like “strong” and “weak” (or “positive” and “negative”) to develop a taxonomy that differentiates various specific atheisms. Unfortunately, this argument overlooks the fact that, if atheism is defined as a psychological state, then no proposition can count as a form of atheism because a proposition is not a psychological state. This undermines Bullivant’s argument in defense of Flew’s definition; for it implies that what he calls “strong atheism”—the proposition (or belief in the sense of “something believed”) that there is no God—is not really a variety of atheism at all. In short, his proposed “umbrella” term leaves so-called strong atheism (or what some call positive atheism) out in the rain.