 According to the proponents of middle knowledge, then, petitionary prayer can still make a difference because God can take into account those prayers that can be offered in the future when God plans how to create the world over time. The mere fact that God knows the future in all of its detail does not mean that this future is determined. So the proponents of middle knowledge have a way to answer the puzzle concerning omniscience. But the theory of middle knowledge is very controversial; critics wonder whether there are truths about what everyone and everything would do in every situation, and even if there were, how God could know such things (see the entry on  prophecy and Zagzebski 2011).