Tag Archives: LEM

omnipotence (Paradox of the Stone)

Related to the classic paradoxes of logic and set theory is the Paradox
of the Stone. One begins by granting the basic dilemma, as an evident
instance of LEM: either God is omnipotent or God is not omnipotent. With
omnipotence, He can do anything, and in particular He can create a
stone, call it /s/, that is so heavy even He cannot lift it. But then
there is something He cannot do, viz. (ex hypothesi) lift /s/. But this
is a violation of LNC: God can lift /s/ and God cannot lift /s/. This
paradox, and the potential challenge it offers to either LNC or the
possibility of omnipotence, has been recognized since Aquinas, who opted
for retaining the Aristotelian law by understanding omnipotence as the
capacity to do only what is not logically impossible. (Others, including
Augustine and Maimonides, have noted that in any case God is “unable” to
do what is inconsistent with His nature, e.g. commit sin.) For
Descartes, on the other hand, an omnipotent God is by definition capable
of /any/ task, even those yielding contradictions. Mavrodes (1963),
Kenny, and others have sided with St. Thomas in taking omnipotence to
extend only to those powers it is possible to possess; Frankfurt (1964),
on the other hand, essentially adopts the Cartesian line: Yes, of course
God can indeed construct a stone such that He cannot lift it—and what’s
more, He can lift it! (See also Savage 1967 for a related solution.)

Contradiction (Stanford Encyclopedia of Philosophy)