 It is also worth noting, in this section, that some philosophers have argued that not only does it make sense to pray for the future if God exists, but also it makes sense to pray for the past as well—such prayers could be effective, depending on the extent of God’s knowledge. For example, given the way we have described effective petitionary prayer, it could be possible for a prayer for something to have happened yesterday to be effective, as long as the thing in question actually did happen yesterday. This is because God could know that I would offer the prayer in the future, and could have taken this into account yesterday, as long as God can know the future. So defenders of middle knowledge and timeless eternity can say that prayers for the past might be effective (but open theists, it seems, cannot say this: for more on this question, see Timpe 2005).