Brian Leftow

In The Metaphysics of Creation and The Metaphysics of Theism, Norman Kretzmann defends an argument for God's existence which he claims to find in Aquinas. I assess this argument's key premise, a principle of sufficient reason, that: ‘PSR2: Every existing thing has a reason for its existence either in the necessity of its own nature or in the causal efficacy of some other beings’. PSR2 requires God's nature to explain His existence. Kretzmann does not tell us how this explanation is supposed to go. I examine such ways as I can envision that God's own nature might explain His existence. None pan out. I argue contra Kretzmann that if God is simple, as Aquinas understood this, His nature does not explain His existence, and while His existence is in itself per se notum (‘self-evident’) this does not entail that it has an explanation. If this is correct, we ought not to read Aquinas as committed to PSR2. Further, if I'm right that it's impossible for ‘the necessity of a thing's nature’ to explain its existence, PSR2 is true only if every existing thing has a reason for its existence in the causal efficacy of some other beings. So, if I'm right, theists ought to steer clear of PSR2, at least read in terms of genuine explanation. I finally offer a weaker reading of ‘a reason for its existence’ which does not generate the problems of the stronger reading Kretzmann seems to have in mind. This too, though, turns out to have its problems.

The doctrine that God is omnipotent takes its rise from Scriptural texts which concern two linked topics. One is how much power God has to put behind actions: enough that nothing is too hard, enough to do whatever he pleases. The other is how much God can do: ‘all things’. The link is obvious: we measure strength by what tasks it is adequate to perform, and God is so strong he can do all things. The Christian philosophical theologian who seeks to explicate omnipotence seeks a convincing account of the reality beneath the ‘phenomena’ of Scripture. This article looks briefly at some historic accounts of omnipotence. It emerges that the early history of the concept emphasized strength more than range of action, with range coming to prominence in Aquinas's day. Three recent attempts to define omnipotence are then considered. All are found wanting, but the author draws morals that help him hazard his own definition.

Before Duns Scotus, most philosophers agreed that God is identical with His necessary intrinsic attributes--omnipotence, omniscience, etc. This Identity Thesis was a component of widely held doctrines of divine simplicity, which stated that God exemplifies no metaphysical distinctions, including that between subject and attribute. The Identity Thesis seems to render God an attribute, an abstract object. This paper shows that the Identity Thesis follows from a basic theistic belief and does not render God abstract. If also discusses how one might move from the Identity Thesis to the full doctrine of divine simplicity and shows that the Identity Thesis generates a new ontological argument

Most debate in the philosophy of religion centres on “thin theism,” the thesis that there is a deity who is omnipotent, omniscient, etc. But few if any theists are just thin theists. For most, thin theism is at best the abstract skeleton of a fuller set of religious beliefs— Christian, Jewish, or Moslem. Thus, there is another set of issues philosophers of religion might but rarely do discuss: with what sort of warrant might one add to thin theism the beliefs of a particular religious tradition? In other words, supposing that thin theism is true, what reasons might there be to be, say, a Christian? Is Christianity True? takes up this last question. Successive chapters ask whether there would be moral benefit in worshipping the Christian God, whether it is reasonable to accept Christianity’s distinctive claims though other traditions which embed thin theism deny them, whether the doctrine of the Incarnation makes sense, whether the doctrine of the Atonement is morally acceptable, whether we know enough about Jesus’s sayings and doings to warrant Christian claims about him, whether the doctrine of the Trinity is coherent, and whether there is a coherent conception of life after death; an appendix takes up Marx on religion.