The common classification of epistemic justification divides it into two types: “internalist” and “externalist.” William Alston, however, particularly in his article “Internalist Externalism,” argues that a theory of justification can incorporate both internalist and externalist components. For him, a justified belief is one based on a “sufficient basis.” He distinguishes between the “basis” and the “sufficiency of the basis”: the internalist element lies in the “existence of the basis,” while the externalist element lies in the “sufficiency of the basis,” which is directed toward the truth of the belief.

The present study critically analyzes and evaluates this view and asks whether Alston’s combined position is defensible. It argues that this view faces three challenges:

1. It has counterexamples: cases exist in which a belief satisfies Alston’s conditions for justification but cannot be considered justified.

2. Alston’s arguments against the internalist nature of the “sufficiency of the basis” also apply to the internalist nature of the “existence of the basis.”

3. Wittgenstein’s doctrine of “hinges of thought” allows an internalist account of the sufficiency of the basis, thereby yielding a unified view of justification and challenging the dual classification.