As established previously it isn’t the case that natural laws exist outside of the universe, so to speak, and force events to progress as they do. But it is an undeniable fact that the universe seems to have a regular structure. I wouldn’t want to say that it was structured as if there were such external laws, because the best way to look at the universe in such investigations is as a whole. And by looking at it as a whole we are looking at it at all times, not just some particular moment. So talking about future events being forced by past events is to bring in time to a timeless situation. Rather we should say that the universe looks patterned, that if we look at a particular state of affairs at an arbitrary location in space and time it is always preceded and succeeded by other states of affairs in a predictable and regular manner. It seems legitimate to ask why this regular pattern exists, instead of chaos or random deviations.
There are basically two ways to approach this problem. We can either attempt to show that universes without a regular structure are impossible or we can use the anthropic principle, and argue that any conscious observers in any universe should expect to observe a universe that appears patterned. The first approach is perhaps historically more popular. Some have suggested that universes that are simple are more likely to exist, and that regularity is a form of simplicity (why? maybe god likes them better). Others have suggested that a universe is not defined by what happens within it, but rather by its regularities and either its initial or final conditions. But the problem with these ideas is that they are just speculation. The available evidence does not favor one of them over any other, and we have no way to rule out the as yet unthought of possibilities, or the possibility that there is no reason, and that the universe we inhabit just happens to be ordered. Certainly there doesn’t seem anything inherently contradictory in the idea of a universe that doesn’t behave completely regularly, and if there isn’t then it will be impossible to prove that the universe must be regular in this way.
Thus an appeal to the anthropic principle seems more likely to provide a satisfactory explanation. Such an appeal results not in an a priori argument for the existence of regularities, but rather an a posteriori one, in which the existence of regularities are deduced in part from the fact that we exist and are conscious. Such an argument admits of the possibility that there are other universes that are unordered, or if there is only one universe, that our universe equally well could have been without any regularities.
To get the argument going we must first look more closely at what regularities are and how the universe might fail to exhibit them. We might think that the law of gravitation is an example of just the kind of regularity we are interested in, but in fact it is not. It is true that the law of gravitation expresses a regularity, but it is not a fundamental regularity. A fundamental regularity is one that governs the interactions of the smallest components of the universe. Other regularities, like the law of gravitation, exist because of these fundamental regularities. A change in the fundamental regularities would result in a change in them, and they could not change without there also being some change in the fundamental regularities.
One way in which our universe might fail to be regular overall is if the regularities change at different times from one set of regularities to another. Such a change however would obliterate any consciousness in that universe. A change in the ways in which the fundamental components of nature interact would result in a change in the way everything works, since those same components make up everything. And thus the way minds work would change as well. And consciousness is a delicate phenomena, changes in the way the mind works are likely to change whether that mind is conscious. Thus a universe in which there are conscious minds can’t be one in which those minds observe a change in which regularities describe the world, because the occurrence of such a change would obliterate those minds. And so we can reason anthropically and conclude that because we exist our universe is one in which the regularities don’t change. Of course this says nothing about whether the universe will remain regular in the future, but given the fact that it has been regular so far, and the fact that there is no way to falsify the hypothesis that the regularities will change sometime in the future, it is reasonable to think that it will remain regular.
Of course it may be that instead of the regularities changing random events happen on occasion that do not fit into the overall pattern of the universe. Now if our universe was a classical universe this might make sense, but our universe is a quantum universe, which means that there is already a small probability that everything that can happen will happen. So to say that an event that breaks the overall pattern occurs is really to say that it has an unusually high probability of occurring, one that doesn’t fit the pattern. But suppose this event actually occurs, what will the inhabitants of this universe think? Well, they will think that they have just witnessed a very improbable event, but not an impossible one. And since improbable events do occur this will not cause them to think that any regularities have been broken. To make them think that this unusual event would have to happen repeatedly, so that the probability of it happening can be observed to be greater than the probability predicted by regularities that are thought to describe the universe. But then they will not be motivated to think that the regularities are being broken, but that there are a different set of regularities in which the probability of that event occurring is higher than they previously thought. So, even if the universe really does contain events that break with every regularity, that fact won’t be known by the inhabitants, who will still conclude that the universe is regular.
So no matter what if a universe contains conscious inhabitants then those inhabitants will conclude that the universe they live in is governed by regularities. And since we are inhabitants of a universe this tells us that we should expect the universe to seem regular. And thus there is no need to further need to explain why such regularities are perceived to exist.