Post Keynesians and some philosophers argue that human beings face not only “epistemological uncertainty,” but also “ontological uncertainty.”
“Epistemological uncertainty” means that the uncertainty we face is a consequence only of the limitations on our knowledge. For example, if one plays a fair game of roulette at a casino, one can calculate objective numeric probabilities for winning at each bet. But one still faces uncertainty about what number will come up on any actual spin. But this uncertainty is “epistemological” in the sense that if you had the relevant information about how the ball was thrown or spun beforehand, a sufficiently advanced physics with sufficiently advanced computers could calculate where the ball would land before it does. One could in theory banish “epistemological” uncertainty with enough information and technology.
But “ontological uncertainty” is something quite different. This is the view that there is a type of uncertainty inherent in reality itself, and, above all, we cannot know the future because that future has yet to be created and is not pre-determined. The future is “open-ended,” and, as we consider events further into the future, the stronger this “ontological uncertainty” becomes, particularly when events are determined by contingent human actions and choices. In other words, this requires that human beings have free will and genuine choice. No amount of scientific knowledge and computing power would allow you to predict future events subject to ontological uncertainty, especially in the medium and long term future in such a world. The barrier to knowledge is not epistemological, it is ontological, because the future is not rigidly determined in the way deterministic physical laws govern the behaviour of a spinning roulette wheel and the landing of a ball.
“Ontological uncertainty” entails that there is an epistemological problem that cannot be overcome, even in principle.
So where does theology fit into this? Classical Judeo-Christian theology holds that god is omnipotent and omniscient.
The property of omniscience entails that god has all knowledge there is (Martin 1990: 287). This is usually understood to entail that god knows the future: that he has perfect knowledge of what will happen in the future – including all human actions – and he cannot be wrong.
So any being x like god that is truly omniscient in this sense must therefore be able to know the future perfectly. If that were true, then in fact our universe has no true “ontological uncertainty” at all. There is only “epistemological uncertainty,” because human beings are not omniscient.
But, more than this, all human actions in the past, present and future must necessarily happen if god is really omniscient and knows perfectly what will happen in the future, because if even one action did not happen as predicted or “known” by god, then god’s omniscience would fail. It follows, under this view, that humans have no free will.
So this view implies that (1) ontological uncertainty does not exist, and (2) that human beings have no free will.
Some Christian philosophers have noticed aspects of this logical conundrum, and they argue that god is not omniscient in the traditional sense at all, and does not have perfect knowledge of the future (Ewart 2009).*
Of course, there are other views. In essence, we have these possibilities:
(1) some entity like god exists and it is truly omniscient, but ontological uncertainty does not really exist, and human beings have no free will;I am inclined to view (3), for many reasons given in the best philosophical defences of atheism (as in Mackie 1982 and Martin 1990), the existence of emergent properties and the failure of strong reductionism, and the evidence for Presentism as a theory of time.
(2) some entity like god exists but it is not truly omniscient, and has no perfect knowledge of the future, which allows humans free will and a type of ontological uncertainty in the universe;
(3) it is probable (for many other reasons) that there are no supernatural beings like god or gods, and we face real ontological uncertainty and do indeed have free will.
(4) it is probable (for many other reasons) that there are no supernatural beings like god or gods, and that the universe is completely deterministic, so that there is no free will and only epistemological uncertainty really exists.
There is real ontological uncertainty, and the future is indeterminate, not only because it does not yet exist, but also because human beings have free will and their choices are open.
* Even more seriously, this line of thought also has devastating consequences for those Christian theologians and Christian philosophers who wish to argue that god is perfectly good because, in his ethics, he is the perfect consequentialist and can foresee all future consequences of any action taken now. For, if god cannot know the future perfectly – particularly if he cannot know in advance the actions that human beings will take with free will – then he cannot even know if any action today is morally good in consequentialist terms, given that he cannot know with certainty if his action will bring about very bad consequences in the future (Martin 1990: 383).
Ewart, Paul. 2009. “The Necessity of Chance: Randomness, Purpose, and the Sovereignty of God,” Science & Christian Belief 21.2: 111–131.
Mackie, John Leslie. 1982. The Miracle of Theism: Arguments for and against the Existence of God. Clarendon Press, Oxford.
Martin, Michael. 1990. Atheism: A Philosophical Justification. Temple University Press, Philadelphia.