附：约翰·斯图亚特·密尔（John Stuart Mill）求因果五法
Mill's five methods in searching of causal connections
There are four experimental principles, or canons, on which causation may be established or partly proven:
1: AGREEMENT: If several instances of a phenomenon all have only one circumstance in common, then that one circumstance is the cause (or effect) of the phenomenon.
2: DIFFERENCE: If a phenomenon occurs in some circumstances but not in others, that which is common to the occasions when it does happen (but not the ones where it doesn't) is the cause.
3: DIFFERENCE AND AGREEMENT: Both the above.
4 RESIDUE: Where a range of factors are believed to cause a range of phenomenons, then take away what is know to cause what and the remaining phenomenon can be attributed to the remaining factor.
...and one more..
5 CONCOMITANT VARIATIONS. Where something varies as another thing varies, so one causes the other (though this one can be tricky).
（中文译文自己搜）。