Causality is a relationship (mostly between two things, or, rather, events, the cause and the effect). Something generates or produces another. Therefore, it is the other's efficient cause and it acts upon it (=it acts to bring it about) through the mechanism of efficient causation. A cause can be a direct physical mechanism or an explanatory feature (historical cause). Of Aristotle's Four Causes (Formal, Material, Efficient and Final), only the efficient cause creates something distinguishable from itself. The causal discourse, therefore, is problematic (how can a cause lead to an effect, indistinguishable from itself?). Singular Paradigmatic Causal Statements (Event A caused Event B) differ from General ones (Event A causes Event B). Both are inadequate in dealing with mundane, routine, causal statements because they do not reveal an OVERT relation between the two events discussed. Moreover, in daily usage we treat facts (as well as events) as causes. Not all the philosophers are in agreement regarding factual causation. Davidson, for instance, admits that facts can be RELEVANT to causal explanations but refuses to accept them AS reasons. Acts may be distinct from facts, philosophically, but not in day-to-day regular usage. By laymen (the vast majority of humanity, that is), though, they are perceived to be the same. Pairs of events that are each other's cause and effect are accorded a special status. But, that one follows the other (even if invariably) is insufficient grounds to endow them with this status. This is the famous "Post hoc, ergo propter hoc" fallacy. Other relations must be weighed and the possibility of common causation must be seriously contemplated. Such sequencing is, conceptually, not even necessary: simultaneous causation and backwards causation are part of modern physics, for instance. Time seems to be irrelevant to the status of events, though both time and causation share an asymmetric structure (A causes B but B does not cause A). The direction (the asymmetry) of the causal chain is not of the same type as the direction (asymmetry) of time. The former is formal, the latter, presumably, physical, or mental. A more serious problem, to my mind, is the converse: what sets apart causal (cause and effect) pairs of events from other pairs in which both member-events are the outcomes of a common cause? Event B can invariably follow Event A and still not be its effect. Both events could have been caused by a common cause. A cause either necessitates the effect, or is a sufficient condition for its occurrence. The sequence is either inevitable, or possible. The meaninglessness of this sentence is evident.