How Does God Know the Future?
Christian theism claims that God is omniscient. With the exception of a recent movement know as “Open Theism”, omniscience has always been taken to entail knowledge of the future. If God is omniscient, then he knows not only everything about the way that the world is, but also everything about how the world will be.
How, though, can anyone know the future? And how, in particular, is it possible to know the future in such detail? There are two models of divine foreknowledgeâ€”the predictive model and the observational modelâ€”that seek to give answers to these questions.
The predictive model of divine foreknowledge holds that God knows the future by prediction, by calculating the way that the world is going to be on the basis of the way that the world is now. There are laws of nature that govern the way that the different entities in the world interact. Using these laws, even we, with our imperfect knowledge, can often make accurate predictions about the future. Think about the way that we calculate the future positions of satellites orbiting the Earth. We know where the satellites are now, and what laws govern their interactions, and so project where they will be in the future.
According to the predictive model of divine foreknowledge, God’s foreknowledge is derived from calculations such as these but on a much grander scale. Given perfect knowledge of the present state of the world, and perfect knowledge of the laws that govern the interaction of its parts, it seems, it should be possible to predict with perfect accuracy the way that the world will be at any given point in the future. This, according to the predictive model of divine foreknowledge, is how God knows, in perfect detail, what will happen in the future.
The problem with the predictive model of divine foreknowledge is that it only works given the assumption that determinism is true. Determinism holds that each state of the world wholly determines the subsequent states of the world; given the way that the world is now, determinism holds, there is only one possible way in which the rest of history could play itself out. This assumption is necessary for the predictive model of divine foreknowledge to work, because if there were several ways in which the rest of history could play itself out then, even with perfect knowledge of the present, and perfect knowledge of the laws of nature, God could not know for certain which of those possible futures would come about. If the present does not determine the future, then the future cannot be predicted with certainty.
Determinism, though, does not seem to be true. Quite apart from the scientific concerns about indeterminacy involving small particles, indeterminacy seems to enter the world through the choices of free agents. If any of us has genuine, significant freedom, it seems, then it cannot be the case that our future actions are determined by the present state of the world. To be a free agent is to be able to react to the world in any one of several ways, to choose which of several possibilities to realise. If there are free agents, then there are many possible futures. Perfect predictive foreknowledge, then, will be impossible.
Some have sought to resolve this problem with predictive foreknowledge by defending a position know as “compatibilism”. Compatibilists hold that we can have significant freedom even in a deterministic world; as long as it is facts about us that determine how we are going to act, they say, our decisions about how to act are free. If this position is defensible, then it allows the theist to hold both that God has perfect foreknowledge on the basis of prediction and that we are free.
An alternative defense of divine foreknowledge, however, is to reject the predictive model of divine foreknowledge and instead advance an observational model. The observational model of divine foreknowledge holds that God knows the future not by carrying out complex calculations about how the present might play out, but simply by observing it. God exists outside time, the observational model holds, and so is able to directly observe different points in time just as we can directly observe different points in space. On the observational model of divine foreknowledge, it doesn‘t matter whether or not determinism is true, because God’s knowledge of the future is based not on predicting how the world will be in the future but on seeing how the world is in the future.