presuppositions of the measurement problem hardly suffices to account for why measurements have determinate outcomes in the first place. No-go theorems on assigning determinate values to observables (the Kochen-Specker theorem and its relatives in particular) make it unattractive to assume that observables have determinate values at all times, so the question arises why precisely those observables which we measure never fail to exhibit determinate values at the end of a measurement process. Even though the epistemic conception of states dissolves the measurement problem in the sense of a sharp antinomy of conflicting assumptions, it does not by itself account for why measurements always seem to result in determinate outcomes. Different epistemic accounts of quantum states respond differently to this challenge, and I postpone the discussion of possible answers to a later stage (see Section 5.2).

The problem of “non-locality”
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The problem of whether quantum theory is compatible with the principles of relativity theory arises perhaps most blatantly in the challenge of reconciling the time-evolution of quantum states including collapse in whatever suitable form with the requirement of Lorentz invariance as inferred from relativity theory. To see this problem in an example, consider a two-particle system in an EPR-Bohm setup 