 The above theorem is stated with two italicized parts, which are the targets of some worries. The merging of the two agents’ opinions might not happen and is only believed with certainty to happen in the long run. And the long run might be too long. There is another worry: the proof of such a theorem requires Countable Additivity as a norm of credences, which is controversial, as was discussed in  section 3.2.  See Earman (1992: ch. 6) for more on those  worries.[8]  For a recent development of merging-of-opinions theorems and a defense of their use, see Huttegger (2015).