Why we cannot do away with everyday causality: an epistemological argument
It is sometimes claimed that causality is an outdated notion. Physical phenomena seemingly affect each other non-locally at a quantum level, meaning that there is no spatial proximity that could explain the process. Similarly, the mind seems to be affected by the brain and vice versa whereas both clearly belong to different ontological categories. According to some, all such cases strongly suggest that what seems like a causal relation between certain phenomena is in fact an a-causal or non-causal relation, meaning that there is no causation in the everyday sense, but rather a simultaneous manifestation of underlying orderly principles.
If I'm not mistaken, some physicists also seem to believe that time and therefore causation as well are purely subjective phenomena with no objective basis in physical reality. In this view, the perceived temporal chain of events would in fact be simultaneous, or rather non-temporal. If they are right, at least causation in the physical world and its interaction with mind would turn out to be illusory.
In my view, the abolition of causality as a meaningful category leads to an epistemological inconsistency. The notion of causation implies that a certain phenomenon brings about another phenomenon. If causal processes are wholely illusory, this also means that the concepts we use in our minds are never brought about by any contact we have had with the world. This would even hold for the concepts of our own inner subjective reality, such as the concept of phenomenal consciousness, if we were to extend the notion of non-causality to the domain of the mind. In general, the concepts we have of the world would never be based on any type of causal impact the world has had on us. If this were true, we could never have any empirical reason to believe in the validity of our knowledge of reality, because it would become literally impossible to gather any information about reality via our senses (or in the case of the mind, via the inner sense of introspection). More concretely, any information of which we normally assume that it reaches our consciousness through our senses and brain would in fact bear no causal relation to the outside world. If so, on what ground are we to base our belief that there is a non-causal relation between our illusory 'impressions' of the physical world and the physical world itself? We may assume that there is no physical world other than one's own private perception of it (ontological idealism), but if we do not reject the notion of a real physical world, why should there be any relation between such a physical world and our perception of it? Our perception of the physical world would not have been caused by the physical world itself (not even partially) and therefore there can be no empirical evidence for an exclusively non-causal connection either.
The notion of non-causal connections
It is well-known that there are remarkable, orderly relations between phenomena that are regular but non-causal all the same. However, this notion of a non-causal (a-causal) relation is normally traced back to a common causal origin. In other words, the notion of non-causality may be useful against the background of a general theory of causality.
Without real causality and without real impressions on our cognition we could not know anything anymore. This also goes for an exotic notion like synchronicity; the notion of claimed non-causal relations between psychological and physical events can only be meaningful if we do not reject the notion of causality altogether, because without causality, we could not even claim knowledge of physical events or (indirectly) of other minds, let alone of non-causal relations between such phenomena.
A non-empirical source of knowledge of the physical world?
An apparent way out of my line of reasoning could be that we claim that our empirical knowledge of the physical world is not really empirical, in the sense that it did not originate from data that the physical world gave us through sensory perception, but that it would still reflect physical reality. Of course, we could not derive this belief from empirical data themselves. It would be an intuition comparable to moral and aesthetical intuitions. However, this escape route is not reconcilable with a general rejection of causation either. Intuition may be regarded as a non-physical sense and it can only work if it gets correct impressions about reality, meaning if it is causally affected by the world.
As rational scholars, we certainly do not always have to respect common sense, but we do need to remain logically consistent, if we want our ontological and empirical theories to make any sense.
This short paper was published online in 2008.