The term “a cause” is an oxymoron. What is not THE CAUSE is NO cause at all. There is only THE cause or NO cause.
Causation requires at least three things, easily remembered by the acronym, SIN
S = sufficiency. The cause produces the effect all by itself. The cause is completely responsible for the effect.
I = immediacy. The cause immediately precedes the effect. Thus, the statement “the gunshot wound to the head instantly killed him and was the cause of death” is closer to the truth than the idiotic statement “smoking causes lung cancer” (20 or more years after taking up the bad habit).
N = necessity. The cause necessarily produces the effect, implying that no other event can interfere with the effect once the cause has occurred. A Law of Nature type of connection between the two events.