Amongst the most important metaphysical issues in the current debate of philosophy of science, the problems raised by quantum mechanics are certainly puzzling. In particular, Heisenberg’s uncertainty principle, the consequence of the double character of matter in quantum physics, raises the question of what ultimately constitutes the nature of matter. According to Heisenberg, the values of position and momentum (quantity of movement) of a particle cannot be simultaneously well defined in terms of a corpuscular theory. This is because of the fact that matter also behaves in a wave-like manner. Once a measurement of position is made, the possibility of measuring its momentum diminishes, for a measurement of a small volume necessarily “fixes” a particle in a corpuscular manner, thus “hiding” its wave-like function.
In fact, Heisenberg preferred to talk of inaccurate or inaccuracy relations rather than of a principle. This suggests that the uncertainty exists actually because the measuring of, for instance, the position of an electron, is related to the impossibility to determinate its other features; in Heisenberg’s terms “It seems to be a general law of nature that we cannot determine position and velocity simultaneously with arbitrary accuracy”. Now, relatedness does not imply causality in a necessary fashion. Thus it is legitimate to ask about what happens regarding causal relations under the theoretical framework of quantum physics. One of the most striking theories that can be useful in this context is Reichembach’s common cause principle, which states that “if there is a correlation between two events A and B and a direct causal connection between the correlated events is excluded then there exists a common cause of the correlation”. Notwithstanding the problematic character of this possible “common cause”, the direct causal connection between events is under scrutiny; and so is the thinking of an exclusion of it, however contrary to the belief that any event has a causal root on others. My intention in this paper is to expose a possible consequence derived from the uncertainty character of the measurements of ultimate pieces of matter, namely: if we can talk of the absence of causal relations, assuming the uncertainty condition is not just a result of the scientist’s interaction (thus blurring a reality that is causally determined and fixed), but a symptom of an ontologically objective nature.