The Case for a Creator, Chapter 5
The second premise of the kalam cosmological argument is that the universe began to exist. In discussing this premise, William Lane Craig asks the question of whether the universe necessarily had a beginning or whether it could have existed for an infinite amount of time before now. He argues that the former is the only option:
“…if the past were really infinite, then that would mean we have managed to traverse an infinite past to arrive at today. It would be as if someone had managed to count down all of the negative numbers and to arrive at zero at the present moment. Such a task is intuitively nonsense” [p.104].
The fallacy here is in Craig’s implicit claim that it’s necessary to “traverse” the past to arrive at the present. This position assumes that time is like a moving light – a spotlight illuminating moments in succession, briefly making each one the present before moving on to the next. But this assumption is false. There is no moving light of time. As we know from modern physics, in particular the theories of special and general relativity, “past”, “present” and “future” are not intrinsic properties of reality. Those terms are to time as words like “near” and “far” are to space – they do not uniquely single out a particular place or a particular moment, but can only be defined from the perspective of the observer. The moments themselves all exist eternally, and nothing needs to “traverse” them. It’s the sequence of our memories, the so-called arrow of time, that seems to make them flow from one to the other.
“You see, the idea of an actual infinity is just conceptual; it exists only in our minds… it’s not descriptive of what can happen in the real world.” [p.103]
If this is true, then Craig has just dealt a critical blow to his own faith. According to Christian theology, God is omnipotent – able to create any of the infinity of logically possible worlds. But if an actual infinity cannot exist in the real world, then it must be the case that God is not omnipotent; the number of possible worlds he can create must be finite, which must mean there are possible worlds that God does not have the ability to bring about. This argument also rules out omniscience, for the same reason; out of the conceptual infinity of true propositions, there must be some that God does not know. Again, these contradictions do not seem to occur to Strobel the hard-charging journalist.
Craig next (finally!) turns to the science. He gives an accurate summary of the major lines of evidence for the Big Bang – the relationship of galactic redshift to distance, the cosmic microwave background radiation, and the abundance of light elements – and calls Big Bang theory “very securely established as a scientific fact” [p.107]. I won’t quibble with this, although some of his fellow Christians would.
However, Craig does object to a common adjunct of the Big Bang theory, cosmic inflation, which holds that the universe underwent a period of ultra-rapid expansion in its first few microseconds. He gifts us with this absolute gem of a line:
“So even though most theorists accept inflation today, I’m rather suspicious of the whole thing, because it appears to be motivated by a philosophical bias.” [p.107]
Because William Lane Craig, of course, is entirely innocent of such biases.
Cosmological inflation was proposed to solve two problems with the conventional Big Bang theory: the flatness problem (why does the universe have just the right density of matter and energy to give rise to a flat [Euclidean] space-time?) and the horizon problem (why is the universe so homogeneous, when the temperature and distribution of matter should not have had enough time to equalize?). The ultra-rapid burst of expansion solves both these problems by “smoothing out” the early universe, and some of the predictions inflation makes have been confirmed by observation.
Notably, Craig doesn’t cite any evidentiary objections to inflation, and he does concede that most cosmologists accept it. Presumably, the source of his complaint is that although he accepts the Big Bang in general, he doesn’t want science to have an answer for everything; he’d prefer these specific questions to remain unanswered so that he can attribute them to miracles. (We have to leave some gaps for God to fit into!) The “philosophical bias” he’s complaining about is really science’s bias toward solving problems, rather than giving up and declaring “God did it” as soon as we see something we don’t understand.
Other posts in this series: