The Greek philosopher Aristotle stated that one cannot claim to have proper knowledge of anything until one has grasped the cause of it. Whether something exists, happens or changes it is assumed that it is as the result of some cause external or internal to it. The why without which nothing could be or happen. This idea is commonly known as causation or the law of cause and effect. It is applicable to all spheres of human knowledge and if Aristotle is right it is essential for true knowledge. Yet, how easy is it to identify causation in every case and to what degree should we be satisfied with the answer(s) provided? TOK seeks to plumb the depths of knowledge and it should therefore always attempt to address the questions of why as well as the questions of how.

Why does a pen fall if you let go of it? Why did the First World War begin? Why did Hitler invade the Soviet Union? Why does person ‘x’ suffer from hydrophobia? Why do cells divide? Why does the consumption of good ‘y’ increase or diminish? Why do I prefer this painting to that one? Why is there a universe? These and other questions attempt to identify the cause of things, in other words the why of the that and the how. Generally, there will be an accepted answer or a set of possible answers which the student is then expected to produce at the appropriate time. To what extent should the TOK student be satisfied with those answers? A pen falls because of the effects of gravity upon it, but why is there gravity in the first place? Because, because, because … but why?  Why? Why? Can you see the problem?

Causation is a notoriously thorny and challenging issue, and it may not surprise you to know that philosophers have yet to come to an agreement as to its very nature and how it works. For example, please note how often answers to why questions are teleological in nature (from telos = end), they ‘explain’ the meaning of the event in terms of its outcome (i.e. if a cell does not divide it cannot grow or reproduce itself) but not really in terms of the reason why it happens at all in the first place. This is a subtle but oft-missed point, there appears to be a causal answer but in fact it only describes an effect or potential effect, not the cause itself.  Moreover, it is also not difficult to demonstrate that most phenomena within the human or natural realms have a multiplicity of causes and identifying which are the most significant may not always be particularly easy.  Also, let us not forget the most common fallacy associated with causation; Post hoc, ergo propter hoc (after this, therefore because of this). Just because one thing often/always precedes another, it is not necessarily the cause of it.

The most interesting thinker on causation was the Scottish philosopher David Hume (1711–1776).  He posited that causation is made up of three components. First, the near proximity in time and place of the cause and the effect. Second, the fact that the cause always precedes the effect in time. Lastly, what he calls the necessary connection which means that, if the cause occurs the effect will inevitably follow, every time. Hume quickly realised that whilst the first two components are familiar to us through repeated experience, the last one is a matter of assumption as it cannot be proven empirically or logically. We can observe cause ‘x’ and effect ‘y’ but not causation itself, we have to assume a ‘necessary connection’ between ‘x’ and ‘y’ but cannot observe it directly. This has led many to label Hume as a skeptic in this matter although it would be fair to say that no-one seems to have bettered his work on causation since.

We believe in causation but cannot observe it according to Hume, and according to Aristotle one cannot claim to possess complete knowledge of anything without being to answer the relevant why questions. Does this matter? Clearly, the majority of human knowledge works perfectly well without a complete explanation of why things are the way they are or why things happen at all; Natural Scientists after all seem perfectly able to describe how the universe works without knowing why there is a universe in the first place, or describe natural laws without knowing why these particular laws operate and not others. Yet, some cannot help but feel that causation remains an unresolved problem for as Hume pointed out, we believe in causation because we believe in the uniformity of nature, but we believe in the uniformity of nature because we believe in causation – as the man says, go figure!