 Grosseteste presents this argument as follows: “Everything known by God is or was or will be; a is known by God (let a be a future contingent); so a is or was or will be. But a neither is nor was; so it will be. Each of the premises is clearly necessary, as is the inference. So the conclusion is not just true but also necessary, for only what is necessary follows from things that are necessary” (Lewis 2017, 111).  The argument is in two parts: A sound argument without modal premises is presented for the conclusion that an event will occur. It is then claimed that its premises are necessary, and thus, by the principle that entailment transmits necessity from premises to conclusion, that its conclusion is necessary too. In his discussion of this argument Grosseteste focuses on premises formulated in terms of God’s knowledge, but he clearly thinks that a range of arguments having the same form can be constructed, employing in their initial part not only premises about God’s knowledge, but also premises formulated in terms of prophecy or even just past-tensed truths of the form “It was the case that A will exist.”  