The Doxastic Assumption in Coherentist Justification of Empirical Beliefs
In epistemology, knowledge is traditionally defined as justified true belief . A large portion of epistemology is concerned with establishing conditions for adequate justification.
Coherentism is a theory of epistemic justification that opposes foundationalism, which posits that a belief is justified by a chain of reasons that end with certain basic, a priori justified beliefs. Coherentism denies such asymmetry  : justification rests on how well a particular belief coheres with the rest of a system of beliefs (SB). Coherentism rejects the notion of basic beliefs and posits coherence as a necessary condition for epistemic justification .
Coherentism is usually regarded as an internalist account of epistemic justification. While externalist theories posit that the factors determining justification are external to the subject, internalism assumes that they are internal. The doxastic assumption (DA) is held by internalists who argue that a belief can only be justified by other beliefs (e.g. ). My research question concerns empirical beliefs – whether doxastic coherentism can provide a solution for how sensory input can enter the SB to support its justification, so that it is not isolated from empirical reality.
Laurence BonJour  has proposed a unique solution to this problem. He states that coherentist empirical justification necessitates the Observation Requirement: the SB must possess laws which attribute a high reliability to a variety of cognitively spontaneous beliefs (CSBs)  – non-inferential beliefs arising from sensory input  that prima facie enable contact with the empirical .
According to BonJour, justification also requires the cognizer's (justified) meta-belief about his SB's coherence. The doxastic presumption (DP) states that one’s grasp of his SB must be approximately correct for coherentist justification to uphold .
Some philosophers have raised concerns about the validity of this argument: if DP is taken as a premise of an argument justifying meta-beliefs, it must be justified by internal reasons, and those must be justified the same way, leading to infinite regress. If DP is taken to describe meta-beliefs as basic, it introduces foundationalist features .
Aims and Methods
By reviewing different solutions, I aim to show that doxastic coherentist accounts of empirical justification fail in that they require some form of foundationalism or the abandonment of the DA. This offers a way to reconsider the justificatory power of the DA and construct new solutions.
 L. BonJour, The structure of empirical knowledge. Cambridge, MA: Harvard University Press, 1986.
 T. Grundmann, "Bonjour’s Self-Defeating Argument for Coherentism," Erkenntnis, vol. 50, no. 2/3, pp. 463-479, 1999. Available: JSTOR, http://www.jstor.org/stable/20012929 [Accessed April 25, 2023]
 J. L. Kvanvig, "Coherentist Distractions," Philosophical Topics, vol. 23, no. 1, pp. 257-275, 1995. Available: JSTOR, http://www.jstor.org/stable/43154203 [Accessed April 25, 2023]