  The most explicit defense of Contradictory Belief has been via a theory of “Spinozan Belief Fixation” (SBF; Gilbert 1991; Egan 2008, 2011; Huebner 2009; Mandelbaum 2011, 2013, 2014, 2016). Proponents of SBF are inspired by Spinoza’s rejection of the concept of the will as a cause of free action (Huebner 2009: 68), an idea which is embodied in what they call the theory of “Cartesian Belief Fixation” (CBF). CBF holds that ordinary agents are capable of evaluating the truth of an idea (or representation, or proposition) delivered to the mind (via sensation or imagination) before believing or disbelieving it. Agents can choose to believe or disbelieve P, according to CBF, in other words, via deliberation or judgment. SBF, on the other hand, holds that as soon as an idea is presented to the mind, it is believed. Beliefs on this view are understood to be unconscious propositional attitudes that are formed automatically as soon as an agent registers or tokens their content. For example, one cannot entertain or consider or imagine the proposition that “dogs are made out of paper” without immediately and unavoidably believing that dogs are made out of paper, according to SBF (Mandelbaum 2014). More pointedly, one cannot entertain or imagine the stereotype that “women are bad at math” without believing that women are bad at math. As Mandelbaum (2014) puts it, the automaticity of believing according to SBF explains why people are likely to have many contradictory beliefs; in order to  reject P, one must already believe P.[12]