This post has been expanded, edited, and published in the journal Hope’s Reason. View it in full here.
I have run into the idea more than once recently that we should discount things like the teleological argument due to the fact that it happened in the past. The thinking goes that, because an event (the existence of the universe, for example), has happened, the probability of that event happening is 1/1. Thus, people like Dawkins can say, “The fact of our own existence is perhaps too surprising to bear… How is it that we find ourselves not merely existing, but surrounded by such complexity, such excellence, such endless forms so beautiful… The answer is this: it could not have been otherwise, given that we are capable of noticing our existence at all and of asking questions about it” (here).
There are a number of ways to take such sentiment. The first is quite trivial. Of course, if an event e happened, the probability e having happened is 1/1. That’s, as I said, trivially true.
The problem is when people try to use this thinking against something like some forms of the teleological argument. Statistically, some people assert, the odds that the universe would be life-permitting (like the one we observe) must be 1/1, because, we are here, after all, to observe it!
Now, imagine the following:
d: The chances of any one side coming up are (granting a fair die and surface) 1/6. I toss a die (I really just did here) and get a 1.
Now, the equivalent claim of saying that the universe must have been life permitting because we are here to observe it is saying that d must happen, given that it is what did happen. Some people have no problem with asserting this, and indeed say that this should be the case. The fact that something is true, they may argue, means that the probability that it would happen was 1/1.
We can, in fact, reduce this whole discussion to symbolic logic. It is the case that:
Which tells us that, if p is the case, then necessarily p is the case. Those who are arguing as above, however, need a much stronger conclusion, namely, □p. But this simply doesn’t follow from reality. It is the case that p, therefore, necessarily, p. But it is not the case that necessarily p.
The distinction is a simple de re verses de dicto fallacy. It is an elementary error philosophically, but it is easy to commit. I’ve done so in the past (see here for a post in which I caught myself in this confusion). Now, de dicto necessity is “a matter of a proposition’s being necessarily true” while de re necessity is “an object’s having a property essentially or necessarily” (Plantinga, v). De dicto necessity ascribes necessity to a proposition, while de re necessity argues only that each “res of a certain kind has a certain property essentially or necessarily” (Plantinga, 10).
Returning to the idea of past events, such as the universe coming into existence or rolling a die and having it come up as a 1, we can see where this error occurs. Those who deny with Dawkins that we can work out the prior probabilities of the universe being life-permitting because “it could not have been otherwise” are actually committing this basic error. They have assigned the proposition that the universe exists de re necessity, when in reality it is only a de dicto necessity. It is, in other words, true that whatever has happened, necessarily has happened. It is not true that whatever has happened has happened necessarily.
(This post is a very miniature version of a journal article I have under review for Hope’s Reason right now.)
Plantinga, Alvin. The Nature of Necessity. Oxford University Press. 1979.
Thanks to Dr. Timothy Folkerts and Dr. Stephen Parrish for some enlightening correspondence on the above points.
The preceding post is the property of J.W. Wartick (apart from citations, which are the property of their respective owners) and should not be reproduced in part or in whole without the expressed consent of the author.