Thomas Aquinas acknowledged difficulty in comprehending a deity's power. Aquinas wrote that while "all confess that God is omnipotent...it seems difficult to explain in what God's omnipotence precisely consists." In the scholastic understanding, omnipotence is generally understood to be compatible with certain limitations upon a deity's power, as opposed to implying infinite abilities. There are certain things that even an omnipotent deity cannot do. Medieval theologians drew attention to some fairly trivial examples of restrictions upon the power of a deity. The statement "a deity can do anything" is only sensible with an assumed suppressed clause, "that implies the perfection of true power." This standard scholastic answer allows that creaturely acts such as walking can be performed by humans but not by a deity. Rather than an advantage in power, human acts such as walking, sitting or giving birth were possible only because of a defect in human power. The ability to 'sin', for example, is not a power but a defect or an infirmity. In response to questions of a deity performing impossibilities (such as making square circles) Aquinas says that "Nothing which implies contradiction falls under the omnipotence of God." 
In recent times, C. S. Lewis has adopted a scholastic position in the course of his work The Problem of Pain. Lewis follows Aquinas' view on contradiction:
His Omnipotence means power to do all that is intrinsically possible, not to do the intrinsically impossible. You may attribute miracles to him, but not nonsense. This is no limit to his power. If you choose to say 'God can give a creature free will and at the same time withhold free will from it,' you have not succeeded in saying anything about God: meaningless combinations of words do not suddenly acquire meaning simply because we prefix to them the two other words 'God can.'... It is no more possible for God than for the weakest of his creatures to carry out both of two mutually exclusive alternatives; not because his power meets an obstacle, but because nonsense remains nonsense even when we talk it about God.
– Lewis, 18
Rejection or limitation of omnipotence
Some monotheists reject the view that a deity is or could be omnipotent, or take the view that, by choosing to create creatures with freewill, a deity has chosen to limit divine omnipotence. In Conservative and Reform Judaism, and some movements within Protestant Christianity, including process theology and open theism, deities are said to act in the world through persuasion, and not by coercion (for open theism, this is a matter of choice—a deity could act miraculously, and perhaps on occasion does so—while for process theism it is a matter of necessity—creatures have inherent powers that a deity cannot, even in principle, override). Deities are manifested in the world through inspiration and the creation of possibility, not necessarily by miracles or violations of the laws of nature.
The rejection of omnipotence often follows from either philosophical or scriptural considerations, discussed below.
Process theology rejects unlimited omnipotence on a philosophical basis, arguing that omnipotence as classically understood would be less than perfect, and is therefore incompatible with the idea of a perfect deity. The idea is grounded in Plato's oft-overlooked statement that "being is power."
My notion would be, that anything which possesses any sort of power to affect another, or to be affected by another, if only for a single moment, however trifling the cause and however slight the effect, has real existence; and I hold that the definition of being is simply power.
– Plato, 247E 
From this premise, Charles Hartshorne argues further that:
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