On Free Decision is one of Grosseteste’s most influential and substantial philosophical works. Its first half is largely devoted to the problem of reconciling God’s knowledge of the future with human freedom. Much of the importance of this discussion resides in the theory of modality that Grosseteste develops, but it is also of importance for the argument Grosseteste presents for the incompatibility of God’s knowledge of the future and future contingency. Grosseteste correctly takes himself to be presenting a different argument, and different solution, from those found in Boethius and Anselm, who had written two of the most important earlier discussions of the issue.  