Against the unjustified use of probabilities

Let me begin by agreeing with Cheeseman’s basic claimviz., that pure logic is not sufficient to handle all forms of reasoning, and therefore must be embellished with something like probabilities. I disagree, however with his proposed division of labor. This part argues that Cheeseman has underestimated the power of logic, by showing that logic-based systems can perform many tasks which his article claims require the use of probability, and can often perform these tasks better. In particular, it defines (logical) justification and assumption information, and demonstrates how this information can be used for many “inherently probabilistic” tasks. It concludes with my view of how a general reasoning system should combine logic and probability.