 …that present and future events are determined causally by their antecedents. This theory has its roots in the principle of causality or the principle of sufficient reason: all events have a sufficient cause that determines them. Thus causal determinism excludes events that arise ex abrupto, but without stating that this is the only possible and conceivable world: unrealized possibilities exist that, though they are not logically contradictory, cannot come about because they are incompatible with the law of nature, that is with the causal chain of events of this world. Necessitarianism strengthens causal determinism from just this latter standpoint: all unrealized possibilities are excluded and it is held that the current law of nature is the only possible one. (Agnesina 2018: 98)