Let us assume, for the moment, that the theory of evolution, or at least our understanding of it, is somehow incomplete, that it does not adequately and causally explain the beginning and development of life on earth. That life did in fact come to be on earth is indisputable. (Even if you tend toward the extra-terrestrial origin of life, that merely transposes the location of its beginnings.) There are two alternatives in seeking answers to how life began: either it came about by natural processes, or in some supernatural manner.
Natural processes are causal processes. Everything that exists in the natural, material world has a specific identity and behaves according to that identity. Supernatural entities, if they exist, are not subject to causality. That is their nature, or rather, their lack of a specific nature. Since natural entities have a specific nature, that nature can be discovered. Supernatural entities, having no specific nature, are unknowable in principle. To posit a supernatural origin or cause for life on earth, or for any unexplained phenomenon, is to substitute the unknowable for the unknown. In doing so, one abandons any hope of discovering the true cause. One has rejected knowledge, or at least the expansion of knowledge, in principle.
One of the creationists’ favorite methods of lending scientific credence to their views is to quote some astronomically high probability against the formation of life, given our current understanding of science. Regardless of their assumptions, methods or the numbers they come up with, these results are always misleading, and are based on an erroneous view of what probability is, why it arises and what it means. The fundamental mistake is to reify probability, that is, to make it something real, a property or attribute of reality. Probability, in fact, is not real.
What is probability? When we flip a coin, we say that it has a 50% probability of coming down heads versus tails. What do we mean by that? That it will come down both heads and tails? Clearly not, the coin will come down either heads or tails; always one, never both. We mean, of course, that in a series of such flips, one result will occur about the same number of times as the other. But why is this so? Is any given toss truly a random, probabilistic event, or is the outcome the result of external factors acting on the coin? In fact, we could construct a mathematical model of the coin toss, accounting for such things as the initial orientation of the coin, the spin rate and the amount of time the coin spends in the air, and predict with some accuracy the result of any toss if these factors were known ahead of time. When the flipping of the coin is performed by a human being, these factors may vary greatly relative to the small changes necessary to alter the outcome. We could, however, construct a “coin-tossing machine” which could reproduce these factors consistently and thus produce a consistent result. We could then toss a coin with 100% probability, or very close to it depending on the quality of our machine and the completeness of our model, of coming down on whatever side we would choose.
We see then that what we refer to as probability in the outcome of an event can be reduced to unknown or uncontrolled causal factors in the context in which that event occurs. We observe different outcomes in what we consider similar events, and so we say that the possible outcomes of that event have certain corresponding probabilities. But since no two events occur in precisely the same context (if they did they wouldn’t be distinct events) those differences can be attributed to the context in which the event occurs. Probability is a stand-in for what we don’t know about an event’s context.
The critical sleight-of-hand that is frequently made is to switch the concept of probability from being an expression of the unknown context of the event to an attribute of the event itself. The reason this is critical is that it switches probability from being an epistemological tool to a metaphysical existent. It becomes an attribute of reality with independent existence apart from any observed events.
Since probability is not an intrinsic, metaphysical attribute of an event, it cannot be applied to past events whose outcome is known. It is therefore logically improper, and utterly nonsensical, to discuss the probability of life coming to exist on Earth. It does exist. The only task remaining is to seek a cause.
continued (just a wee bit more!):