One definition for "cause" is "a person or thing that gives rise to an action, phenomenon, or condition." It appears that we witness examples of causation (one person/thing causing something else) all around us, yet causation is one of the most hotly debated and mysterious aspects of human experience.
Colin Gunton (The Triune Creator, pages 118-119) relates how "a new theology of nature" developed in the Middle Ages that involved thinkers like Thomas Aquinas (c. 1225-1274) and Duns Scotus (c. 1266-1308) positing that A causes B (a cause produces an effect). This idea did not originate in the Middle Ages, but from the idea, Aquinas and Scotus inferred that A entails/is implied by B. So now one could think of causation in terms of logical relations (logical implicates) or what logicians call sequents.
Causation seemed to be in peril when David Hume (1711-1776) maintained that cause and effect could not be explained by appealing to rationalist (analytic a priori) or empiricist (synthetic a posteriori) principles: Hume insisted that cause and effect relations (causality) are reducible to habituation. To put it simply, we often witness one event (B) following another event (A), so we then come to believe that B follows A out of some causal necessity. For instance, the car accelerates after I put my foot on the gas pedal or the light in my house comes on after I flick the light switch. However, Hume pointed to alleged difficulties with the customary account of causation/causality; he asked that the causal connection between A and B, be shown empirically, which evidently cannot be done. However, even if one tries to demonstrate the causal link by using analytic a priori reasoning/methods (i.e., rationalism), the result is still unsatisfactory since it's nigh impossible to ubiquitously apply the concepts of rationalism to the multiple events happening in the natural world. So it seems that things are at an impasse.
On the other hand, Immanuel Kant was intrigued by the challenges of David Hume. He said that he was awakened from his "dogmatic [Wolffian] slumbers" by Hume, which meant that Kant had to reorient the way he viewed epistemological and metaphysical puzzles. After considering Hume's thought on causes and their effects, Kant suggested that while neither rationalism nor empiricism could explain causation satisfactorily, appealing to synthetic a priori considerations could. In other words, causation becomes a mental category, but one limitation of Kant's approach is that a conceptual "solution" is set forth that we still cannot apply to the "real world." In philosophical terms, Kant's answer may satisfy epistemological criteria but it leaves metaphysical concerns untouched.
Thomists (students/adherents of Thomas Aquinas) think they have an adequate response to Hume's challenge: they use Aristotle's theory of hylomorphism and his account of four causes to account for one thing causing another in the real world, thereby not just reducing causality to something mental or apparent. In this post, I am not attempting to say which account of causation/causality is correct: what I'm really trying to achieve is to show the untenability of rejecting causation/causality as extramental categories. Secondly, I submit that positing only natural causes (secondary causes) seems unreasonable or untenable. After all, one can posit a natural cause for the beginning of the universe but how that cause came about or why it brought the cosmos into existence just remains a brute fact without any genuine explanation. The famed question of Leibniz is pushed to the side or ignored: Why is there something rather than nothing? Saying that some random material occurrence/event brought the cosmos into existence is not an explanation, especially when it comes to explaining life and its great diversity.
This topic is a big one that a single blog post can't fully address, but I've merely tried to spark reflection on this difficult topic. Numerous thinkers have challenged Hume. Not only Kant, but Edward Feser offers refutations of Hume as does Elizabeth Anscombe and Lady Shepherd. John Searle is another theorist who offers rebuttals of Hume's causal thinking and he does so without appealing to God. I think Aquinas would likewise set forth arguments that could test Hume's challenges, and I sometimes wonder what Hume would think of examples like pregnancy or the way that cars work with multiple causes/effects taking place as they operate. I've never seen or heard of a causeless pregnancy: even the Virgin Birth had a cause, according to Scripture and the church fathers. As Hebrews 3:4 reasons, every house has a builder, so the universe needed a builder too. Show me one house or material object that ever came into existence on its own, uncaused.
Of course, I know one Humean response to this line of reasoning. He will say that what applies to the part does not necessarily apply to the whole; we know that it takes someone to put a car together and we know something about building houses and other structures, and we know something about getting pregnant and having children. Nevertheless, Hume might say that we know nothing about building a world. This might be true but Frederick Copleston offered the reply that while one can't infer that what applies to the part always applies to the whole (water is wet, but its constituents are not), it would be a mistake to reason that mereological relations could never be viewed that way (e.g., a fence composed of white pickets is also white as a whole).
As for Hume's reasoning that we know nothing about building worlds, there's a lot of things we don't know, but we can't rule out causation/causality regarding those things for that reason alone. At one time, we knew very little about pain control: while there is much to be learned about controlling pain, we now know much more than our forebears did. The same principle applies to the periodic table of elements and our knowledge of gravitation--think too about the advances in technology that would have been unthinkable to people living a millennium ago. Of course, we have never built an entire cosmos and we cannot. But does that mean that we need to rule out causation of the cosmos based on our inability to produce a universe or know how to bring one into existence?
G.E.M. Anscombe, whom I mentioned earlier, thought of causation this way: If there is a cause, then there is an effect, all other things being equal. See more about her account of causation here: https://iep.utm.edu/anscombe/#H3
She argues that we witness events taking place often wherein one thing appears to be caused by another. At least, that would be the reasonable inference (e.g., drinking a glass of water and the glass becoming empty). This is a retort to Hume's suggestion that we never see the causal link between event A and event B.
Suggestions for Further Reading:
Feser, Edward. Scholastic Metaphysics: A Contemporary Introduction. Editiones Scholasticae, 2014.
Anscombe, G.E.M. “Modern Moral Philosophy,” Philosophy 33 (1958): 1–19; reprinted in [Ethics, Religion, and Politics], 26–42. [CAD] Causality and Determination: An Inaugural Lecture, Cambridge: Cambridge University Press, 1971; reprinted in [Metaphysics and the Philosophy of Mind], 133–147. See also https://plato.stanford.edu/entries/anscombe/
Compare https://philosophy-science-humanities-controversies.com/listview-details.php?id=782709&a=&first_name=Peter%20van&author=Inwagen&concept=Causation



