In philosophy, science, and everyday language, causality refers to the relationship of cause and effect.
- cause, the correlate of the effect, is “what makes a thing do or act as it does”; this produces the effect;
- causality is the “current relationship of cause and effect”.
History of the concept
Plato often returns to the principle of causality. He attacks Anaxagoras, who, after having mentioned the universal Spirit, remains to the material causes, “actions of the airs, the ethers, the waters, which he invokes as causes.” In Phileus and The Sophist, he distinguishes four genera: the cause of decomposition (the Other), the mixing cause (the Same and the Rest) the unlimited (the Movement), the limit (the Being). In Timaeus, he develops his thought: “We are obliged to speak of the two kinds of causes, while distinguishing between all those who are intelligent and produce beautiful and good things, and all those who, lacking reason, produce every time their effects at random and without order.” “The rest always resides in uniformity, and movement is a passage to the absence of uniformity, moreover the cause of the absence of uniformity is inequality” . “Without necessary causes it is impossible either to apprehend the divine causes themselves, which are the only objects of our preoccupations, nor afterwards to understand them or be part of them in any way”.
In the Aristotelian system, the principle of causality is central. To know is to know the cause (aitia). “We think we know everything scientifically in the absolute sense when we think we know the cause of the fact of which the thing is, knowing that it is the cause of the thing and that that thing cannot be otherwise than it is not.” Aristotle distinguishes four causes: the material cause (what the thing is made of), the formal cause (the essence of the thing), the driving cause (“from which there is a principle of change or rest”) , and the final cause (in view of what the thing is). “One calls cause, in a first sense, the immanent matter of which one thing is made: the brass is the cause of the statue … In another sense, the cause is the form and the paradigm, meaning the definition of quiddity; for example, for the octave, it is the ratio of 2 to 1, and, in general, the number … The cause is still the first principle of change or rest: the author of a decision is the cause of the action … The cause is also the end, that is to say the final cause. For example, health is the cause of the walk.”
Skeptics, including Sextus Empiricus, have criticized the notion of cause. “We start to doubt the particular causal explanations, thus refuting the dogmatists who attach a great interest to it … Aenesidemus transmits to us eight modes, which, according to him, are apt to manifest the vanity of any dogmatic etiology.” We cannot conclude phenomena from causes, like signs to signified things, for to understand a sign we must already know the signified thing. We can only conclude phenomena to phenomena, appearances to appearances. One can only grasp their relations of succession or simultaneity in time.
David Hume says that we see the movement of a ball, then the movement of a second ball encountered by the first, but we do not see the active energy, the effective power, the cause that produces the motion. “All events seem entirely detached and separate. One event follows the other, but we can never see any connection between them. They seem to be linked by conjunction, but never by connection.”
To linear causality, the twentieth century added circular causality.
Edgar Morin takes up the different forms of causality used in various sciences and announces the emergence of complex causality. He evokes circular causality as a causality, at the same time self-generated and generative. “Circular causality, ie retroactive and recursive, constitutes the permanent transformation of generally improbable states into locally and temporarily probable states”.
Principle of causality
The principle of causality is stated as follows: “Every phenomenon has a cause”. As Spinoza writes: “Of a definite cause necessarily results an effect; and, conversely, if no definite cause is given, it is impossible for an effect to occur.” Kant asserts: “Law of causality: All changes happen according to the law of connection of cause and effect”.
Bertrand Russell says that “The law of causality, I believe, like much that passes muster among philosophers, is a relic of a bygone age, surviving, like the monarchy, only because it is erroneously supposed to do no harm.”
Causal realism states that causation is a fundamental feature, that the properties, including the fundamental physical ones, are dispositions or powers to produce certain effects.
Causal realism implies that causation cannot be reduced to other features of the world, such as, for instance, certain patterns of regularities in the distribution of the fundamental physical properties. Causation consists in one event bringing about or producing another event, being a relation of production or bringing something into being. (Michael Esfeld, “Causal realism”)
Causal realism is a power inherent in the world to produce effects independently of the existence of minds or observers. Certain problems in the philosophy of mind are artefacts of causal realism because they presuppose the existence or possibility of a real causal nexus between the ‘physical’ and the ‘mental’. These dilemmas include (but are not necessarily limited to) the ‘hard problem’ of consciousness and the problems of free will and mental causality. Since the ostensible causal nexus cannot be directly perceived, it is sublimated into obscure and elusive phenomena along the purported mental causal chain. (Ben Gibran, “Causal Realism in the Philosophy of Mind”)