Wednesday, October 5, 2022

Induction to the Causal Principle?

I’m curious whether one can infer the causal principle C that everything that comes into existence has a cause inductively on the basis of our observations of things with causes.

There are a couple of issues with such an inference. First, let’s think about the inductive evidence about causes globally. It seems to consist primarily in these two observations:

  1. we have found causes for many things that come into existence, but

  2. there are many things that come into existence for which we have yet to find causes.

It is worth noting that in terms of individuals, (b) vastly outnumbers (a). Consider insects. Of the myriad insects that we come into contact daily, we have found the causes of very few. Of course, we assume that the others have causes, causes that we suppose to be parent insects, but we haven’t found the parents.

For observations (a) and (b) to support C, these observations have to be more likely on C than on C’s negation. But now we have two problems. First, on the negation of C it doesn’t seem like we can make any sense of the probability that some item has or does not have a cause. Causeless events have no probabilities. Second, even if somehow assign such a probability, it is far from clear that the observations of (a) and (b) are more to be expected on C than on not C.

Second, I suspect that often when we claim to have found y to be the cause of x, our reason for belief that y is the cause of x depends on our assumption of C. Our best candidate for a cause of x is y, so we take y to be the cause. But I wonder how often this inference isn’t based on our dismissing the possibility that x just has no cause.

None of this is meant to impugn C. I certainly think C is true. But I think the reasons for believing C are metaphysical or philosophical rather than inductive observation.


Tom said...

This could help furnish a response to Felipe Leon's pre-existing material cause argument against creatio ex nihilo, which argues that we have the same basis for believing all causation must involve a pre-existing material base as we do for assuming that everything that comes into existence has a cause.

On the other hand, in some of your writings you do appeal to inductive arguments, namely that we would expect things to constantly pop into existence without a cause if the causal principle were false, and so the orderliness of nature is evidence against the possibility of things coming into existence. Your point that we seem to reason from the causal principle to individual cases of cause and effect is intriguing, and could maybe help justify both our practices of causal reasoning and our obvious belief that things won't suddenly start popping into existence uncaused.

ASBB said...

Your penultimate paragraph suggests a new argument:

(1) We are justified in inferring the existence of a parental cause for any insects known to exist
(2) If (1) is true, then C is true
(3) Therefore, C is true.

ASBB said...

Another thought: I suspect that the inference to the existence of a cause is on an epistemic par with an inference to the consistency of some event with the laws of nature.

For any of the unfathomably large number of episodes of motion I observe, how on Earth do I know that they're actually consistent with the laws? Think of the water falling from my shower head, the ambulance of an old man through a doorway, or the slide of a coffee cup from the counter to my hand. Do I really know that those motions were consistent with the laws instead of one of an infinity of possible ways that could technically violate those laws? I don't know the details of the motion, and I don't even know how to check if those details - even if I knew them - were consistent with the laws. But I infer that they are. This seems totally legitimate on whatever epistemic grounds exist for the scientists who conclude what the laws are.

Now, (a) and (b) become (a*) We know of many events that conform to the laws and (b*) there are many events for which we have no idea if they conform to the laws. All the same arguments seemingly can be run (with the exception of the no probability argument) against the view that our nomic beliefs are correct.

It seems that the denial of our causal inferences are no worse off than our nomic inferences.

Walter Van den Acker said...


Nothing can come into existence because ex nihilo nihil fit.
But even if this were possible, in order to inductively infer that something coming into existence must have a cause, one must actually observe something coming into existence as well as its cause.
It is not enough that we obeserve causes for every single insect and every other animal or plant, because all we have observed in that case is transitions from one type of being to another, not the coming into existence of a brand new being.

Alexander R Pruss said...


I am OK with arguments from our expectations. Those are not inductive arguments based on our observations of things having causes, but are _a priori_.

Regarding things popping into existence, I have come to feel the force of the thought that no probabilities can reasonable be attached to such causeless popping. But sometimes I argue concessively, granting that some probabilities can be attached.

Fr M. Kirby said...

It seems to me that while (a) and (b) are indeed insufficient to inductively ground C, in accordance with Dr Pruss' arguments, another observation I will call (c) tips the balance. Here it is:

We consistently find causes for individual things that come to be when we have sufficient opportunity to investigate their origins. In other words, the set of (a)-type things consistently grows at the expense of the other set as knowledge of the things increases.

Alexander R Pruss said...

Fr Kirby:

That's very interesting. Maybe then the way to respond to my point about insects is this: when we've had "sufficient opportunity" to observe an insect to such a degree that *if* it had parents then we would have been able to identify them, then invariably we have identified the parents. And similar conditionals are true for other things.

Fr M. Kirby said...

Yes, though I admit it might be difficult to define "sufficient opportunity" in practice without smuggling in implicit assumptions that risk reducing the inductive argument to circularity. In other words, if what allows us to judge the sufficiency of opportunity to find a cause is related to how ever much effort it takes to successfully find such a cause, my (c) becomes "We consistently find causes for things that come to be when we have investigated their origins up to the point when we find causes for them", which is tautological.

The trick would be to define "sufficient opportunity" rigorously without unintentionally sneaking in the epistemic assumptions we are trying to ground. And, even if we succeed in doing so, I suspect that in the real world, both the common folk and academics, especially in science, are accepting C in practice at least, and without such a strictly valid and non-circular grounding. To put it another way, I believe there is at least as much faith/intuition as reason (in the narrow sense) subjectively underlying both C and the confidence in nomic inferences to which ASBB refers.