Is All Knowledge of Causation Inductive?

 Is All Knowledge of Causation Inductive?

Blake Denenny

      Hume famously posited that all causation is known by induction, by the experience of constant conjunctions of events, and ergo the principle of causality is either flimsy or vacuous. To use an example, we expect that fire will burn paper because we’ve seen it happen consistently, but there is no logical connection between the two events. We could imagine that one day, even a normal piece of paper would refuse to burn: causes and effects are inherently “loose and separate,” and there is never any strictly logical connection between them, according to Hume. 

       Now, there’s certainly something to what Hume is getting at: after all, no Christian has ever claimed that the miracles in the Bible are logical contradictions. But nevertheless, the stories in the Bible don’t contradict the principle of causality as such because they emphatically assert a cause, namely God. There’s no question that many cases of cause and effect are known through induction (which is why the natural sciences are empirical rather than a priori) but this can’t be the entirety of the story.

      For one thing, Hume’s argument becomes circular: he claims that our notion of causation is caused by the experience of the constant conjunctions of events. To even make a claim as to the origins of our ideas and beliefs is itself to presuppose the reality of causality, and this type of causation cannot itself be reduced to observations of sense. Hume, in his analysis of causation, essentially limited himself only to the physical “befores” and “afters” (which are admittedly “loose” to varying degrees), but there are also types of physical causality which are much “tighter” (namely, essentially ordered causes) and a realm of mental causation which is also much “tighter” than these “loose” types of “before and after” causation.”

      To use an example of physical causality, one could say that my ability to stand is, in a sense, caused by the earth’s existence. While it would certainly be odd to say such a thing, it is nonetheless true that my ability to stand here and now depends upon the earth’s here and now existence, and this dependence could be considered to be a type of causality. What distinguishes it from Hume’s “loose and separate” examples of causation is the simultaneity of the connection. To say that we know by induction, or by a generalization of particular cases, that we require the earth’s existence to walk is dubious at best. To use another example, if I were to pick up an apple, I can say with certainty while I’m picking up the apple that the apple is being picked up by me: there is no “before” or “after” in this one event, and so knowledge of these types of causation can’t be said in any way to be inductive or a generalization from repeated events because we see the simultaneity of cause and effect in a single instance. What would it mean to be mistaken about such a case?

      The problem of ascribing all knowledge of causation to induction becomes even more pronounced when we analyze forms of mental causation. For instance, if I were to believe that someone’s name is John because they told me so, my belief can be said to have been caused by John’s assertion. Of course, the belief wasn’t logically necessitated by this assertion, as I could’ve doubted it for whatever reason, but we could not say that this instance of cause (John’s assertion) and effect (my belief) is loose and separate, because there certainly is a logical connection between the two. Of course, one could say that I would’ve been applying probabilistic reasoning in the act of believing John (since I didn’t see his birth certificate and saw no reason to doubt his assertion) but my point is that there is usually a logical connection between beliefs (effects) and causes (observation/experiences), while Hume was denying that there was ever a logical connection between causes and effects. Even if we were to undertake the radical skepticism of Descartes, causal language still seems impossible to avoid, because we would have to say that our belief in an external world was caused by the appearance of an external world. 

      There’s also the problem of what I would call “meta-causality,” meaning that we can know with certainty aspects of causality as such, and this knowledge cannot itself be reduced to induction or observations of sense. For instance, we know that causation is a necessary condition for the world to be rational, for the possibility of scientific knowledge, and maybe even for the existence of intelligent observers. We can also distinguish between different types of causality and the degrees of certainty that attend to them. That type of knowledge about the importance of causality or the principle of causality as such cannot itself be inductive or empirical knowledge because all empirical knowledge presupposes this a priori knowledge of causality. And so on…

    But can causality be clearly defined? To paraphrase Augustine, “I know exactly what causation is, until I’m asked to define it.”