probabilist

n. [ Cf. F. probabiliste. ] [ 1913 Webster ]

1. One who maintains that certainty is impossible, and that probability alone is to govern our faith and actions. [ 1913 Webster ]

2. (Casuistry) One who maintains that a man may do that which has a probability of being right, or which is inculcated by teachers of authority, although other opinions may seem to him still more probable. [ 1913 Webster ]