A question about speaker meaning and semantic meaning. (I probably should know the answer to this, but what are blogs for except for revealing one’s ignorance?) Consider the following little passage, taken perhaps from a discussion of the evolution wars:

Creationists believe that contemporary biology is founded on a giant mistake. Humans were created directly by God in His own image. They are not descended from other primates.

I know what the speaker meaning of the last sentence is: Creationists believe that humans are not descended from other primates. But is that the semantic meaning of the sentence, or is the semantic meaning simply that Humans are not descended from other primates? Or is the semantic meaning just a propositional radical The xs are not descended from other primates?

I generally assume speaker meanings and semantic meanings are identical unless there is a good reason to say otherwise, so I am inclined to think they are the same here, but there are some pretty good authorities saying this is very foolish of me.