Necessary Existence
Necessary Existence
Philosophers in the Islamic tradition have been especially committed to articulating the thesis that God's existence is the concept of a reality that is not contingent. One way they (and later, Christian thinkers) express the concept is by claiming that God's essence (what it is to be God) contains existence. With respect to everything else in this world, essence (what a thing is) is distinct from existence (the fact of a thing existing or not existing). At one time horses did not exist, and one day horses will likely cease to exist. (Astrophysicists conjecture that when the sun uses up all of its hydrogen four billion years from now, the earth will vaporize.)
The concept of God, however, is not contingent because (if there is a God), God never came into existence nor can God cease to exist. God's essence is existence. To be God is to exist. To ask why God exists would be like asking, “Why is red, red?” The color red simply is red. The redness of red is simply a matter of the law of identity: A is A, or every thing is itself. Similarly, if there is a God, then there is a being whose reality is not derived from another force (a super God) and whose nonexistence is implausible.
Dawkins has complained that if theists are allowed to posit the necessary existence of God, then he ought to be allowed to posit necessary existence of the cosmos. There are two problems with this. First, theists do not begin with some arbitrary concept, x and then add on necessary existence. Their reasoning, rather, is that necessary existence is part of the existence of God. If someone were to report, “Oh, God existed at noon today and then perished at 2:00 PM,” we would normally think the person was joking. The concept of God simply is the concept of a being that cannot be vulnerable to nonexistence. Second, there does not appear to be anything in the cosmos or about the cosmos that involves necessary existence. The fact that science must observe the world in order to explain it is evidence that the world could have been different. The concept of the cosmos is contingent; various scientific theories explaining the way that the world works may have conditional necessity (a quark must have a certain electric charge, given the prevailing laws of physics), but nothing in or about the cosmos is essentially necessarily existent, nor are the laws of physics themselves necessary. There are current laws of the conservation of energy, but none of them provides any reason to think that energy itself necessarily exists. The mere endurance of some force or event over time, even if it is without beginning, does not itself constitute necessary existence.
Consider the following objection, however. Can't we conceive of a cosmos without God? If so, it seems that it is possible that God does not exist. If it is possible that God does not exist, then God's existence is not necessary.
Reply: Conceiving of the nonexistence of God is more difficult than it may appear at first glance. I can conceive of a cosmos without conceiving of the truth 1 + 1 = 2, but it does not necessarily follow that I am conceiving of a cosmos in which 1 + 1 does not equal 2. If one can see that God's existence is impossible the way one can see that 1 + 1≠3, then there is no problem with grasping the possibility of God's not existing. But short of an argument that God's existence may be known to be impossible, the objector would need to do two things: (1) conceive of God and (2) conceive of that God's not existing. This, we suggest, is difficult because (by definition), acknowledgment of God's existence is necessary to conceive of God's nonexistence. To conceive of God's nonexistence without conceiving of God would be like conceiving of water without hydrogen or oxygen. You may think that you could have water sloshing around in a container while clever scientists rename all the oxygen and hydrogen atoms, but because water is H2O, this is not a bona fide possibility. God's existence, unlike that of the cosmos, is necessary.