ABSTRACT : After introducing the notion of mental language as it was developed especially by William of Ockham this article focuses on the role of mental sentences in the logical interpretation of belief-ascriptions. First, the divergent positions advocated by Frege and Searle are outlined. Next, it is asked how the fourteenth- century Parisian logician Jean Buridan might hare handled such statements as "The sheriff believes that Mr. Howard is an honest man'. It is concluded that in spite of many superficial differences, at bottom Buridan's view is rather similar to Searle's account. In particular, both authors hold that in reported speech the words 'Mr. Howard is an honest man' keep their usual meaning as far as reference and predication a...