Ok, so I've seen this argument thrown around a lot, and I've seen some of the responses to it. Honestly, I don't find any of them to be that effective. The KCA is a terrible argument, but a lot of the objections are terrible as well. So, I'm going to try and dismantle the argument entirely, using its own terms and assumptions. Hopefully, people can just link to this every time the argument comes up. My goal is to keep the KCA from ever, ever, being used on this forum again.(I took this from a debate I did on the topic.)
The argument
Modern day theists use the Kalam Cosmological Argument to establish the existence of god, who is defined as the timeless, spaceless, beginningless, immaterial, probably omnipotent, and personal cause of the universe. The argument has three premises.
P1: Everything that begins to exist has a cause.
P2: The universe began to exist.
C: The universe had a cause.
By deductive reasoning, that cause is established to be god.
God caused the first state of time to exist
The KCA assumes that there is some state of time that is not preceded by any other state of time. We will call this the initial state of time, which is state of time that is not preceded by any other state of time. On a theistic view, all of matter, space, and energy came into existence in this initial state of time. The theist asserts that everything which begins to exist has a cause, so the beginning of all of these things requires a cause.
My goal is not to show that the casual principle is wrong, or that the universe is eternal or oscillating. I agree with the first two premises of the argument. My only goal is to show that the initial state of time cannot exist, so god cannot have caused it. If god cannot have caused it, then he cannot exist, because god is defined by the KCA as the cause of the initial state of time.
Theists such as William Lane Craig appeal to the Big Bang in order to show that the universe had a beginning (http://www.reasonablefaith.org/the-crai ... #section_2). I don't disagree with this, and I too think that the universe had a beginning. It's significant because the theory of relativity proves that we don't live in a static universe, a discovery which helped the Big Bang theory get developed. One of the major proofs of the Big Bang is that the universe can't be static. If the theory of relativity is wrong, then the best proof of the Big Bang theory is also wrong. It would be very awkward for a theist to deny the theory of relativity, because it has implications on the Big Bang. If you invoke the Big Bang, you invoke relativity. If you deny relativity, you can't invoke the Big Bang. It's difficult, if not impossible, to prove premise two without the use of relativity. (http://www.pbs.org/wgbh/nova/physics/re ... osmos.html)
I shouldn't argue by implication only, however. There are many proofs of general relativity, some complex and some simple, so I will show that relativity is true using one of the simpler arguments. For many centuries, it was noted that the orbit of Mercury was slightly different from what Newton's equations would predict. Instead of orbiting in a perfect ellipse like other plants, the orbit of Mercury precesses (which means it does not return to the same point after one orbit, but shifts slightly). When Einstein calculated the orbit of Mercury using the equations of general relativity, it predicted the orbit of Mercury with perfect accuracy. This is a strong indication that the theory of relativity is true. (http://en.wikipedia.org/wiki/Tests_of_g ... of_Mercury)
This leads us to a problem with the KCA that has been ignored by theists in the mainstream literature. It's even ignored by atheist philosophers. If the theory of relativity is true, then there cannot be an initial state of time. The theory that the KCA assumes ends up being its demise. There are equations derived from the theory of relativity called the 'Friedmann-Lemaitre-Robertson-Walker' metric. This metric describes a universe that is homogeneous, isotropic, and expanding universe (http://plato.stanford.edu/entries/cosmo ... ology/#2.5). These metrics also state that every finite interval of time is half-open. This means that if you have a finite interval of time, such as an hour, you can divide that state into half an hour and another half an hour. An initial state of time is a finite interval, ergo, it is half-open. But if it is half-open, then it cannot be an initial state, because you can divide it in half.
The KCA assumes that there is an initial state of time. Premise two of the KCA assumes the theory of relativity. The theory of relativity contradicts the assumption that there is an initial state of time. Therefore, the KCA false, because its assumptions contradict one of the most proven theories in all of science.
A Personal Cause of the Universe
The KCA depends on the idea of simultaneous causation (http://www.apologeticspress.org/apconte ... rticle=687). Simultaneous causation is the idea that ‘’the causal order must not be the temporal order because of the possibility of cause and effect being contemporaneous.’’ (http://plato.stanford.edu/entries/causa ... taphysics/) This is another instance of the KCA causing its own demise. The possibility of simultaneous causation allows us to explain the existence of matter without reference to a personal cause. Imagine atoms A, B, and C. A comes into existence and instantaneously causes B, which instantaneously causes C, which instantaneously causes A. All of the atoms have causal explanation, and they all begin to exist at the exact same time. Using the assumptions of the KCA, it can be demonstrated that there is no need to have a personal cause of matter.
Quentin Smith gave a talk that demolishes the idea of a personal cause (http://www.infidels.org/library/modern/ ... heism.html). He mentions the development of the Wave Function of the Universe by scientists such as Hawking and Vilenkin. It ‘’implies that it is highly probable that a universe with our characteristics will come into existence without a cause. Hawking's theory is based on assigning numbers to all possible universes. All of the numbers cancel out except for a universe with features our universe possesses. For example, contains intelligent organisms such as humans. This remaining universe has a certain probability very high -- near to a hundred percent -- of coming into existence uncaused.’’ The Wave Function also has a large amount of evidence to support it: ‘’This theory predicts our universe has evenly-distributed matter on a large scale, which would be on scales of super-clusters of galaxies. It predicts that the expansion rate of our universe -- our universe has been expanding ever since -- would be almost exactly between the rate of the universe expanding forever and the rate where it expands and then collapses. It also predicts the very early area of rapid expansion near the beginning of the universe called inflation. Hawking's theory exactly predicted what the COBE satellite discovered about the irregularities of the background radiation in the universe.’’ The universe came from ‘’a timeless space, a four-dimensional hypersphere, near the beginning of the universe.’’ This demonstrates that a personal cause is not needed, but more importantly, it demonstrates that a personal cause is unlikely. As Smith says: ‘’For the wave function of the universe implies there is a 95% probability that the universe came into existence uncaused. If God created the universe, he would contradict this scientific law in two ways. First, the scientific law says that the universe would come into existence because of its natural, mathematical properties, not because of any supernatural forces. Second, the scientific law says the probability is only 95% that the universe would come into existence. But if God created the universe, the probability would be 100% that it would come into existence because God is all-powerful. If God wills the universe to come into existence, his will is guaranteed to be 100% effective.’’
Conclusion
The KCA has many assumptions. It assumes the Big Bang, so it also assumes relativity. Even if it didn't, the theory of relativity is obviously true anyways. It also assumes that simultaneous causation is possible. Using these two assumptions, it can be demonstrated that the KCA is wrong on its own terms. God cannot cause an initial state of time, and matter can come without reference to a personal cause.
The scientific evidence also demonstrates that a universe such as ours is probable, and that a personal explanation is confirmed to be unnecessary and implausible.
So there you have it. This argument should never be used again on this forum. Feel free to link this if it ever comes up again.
