[概念] Necessary and Sufficient conditions

C -> E

則 E 是 C 的必要條件
C 是 E 的充分條件

1. C produces E2. the occurence of C makes the occurence of E unavoidable
_________________________________________________

E causes C if and only if......

意思是 E 是 C exists 的必要條件

我最近常吃麵包, 所以一下舉了個麵包的例子, 方便了解.

E belongs to a set of condition A(materials of making bread) that arejointly sufficient to give rise to B.
_________________________________________________

腦內大激盪!

這是一個叫John Mackie寫的==>INUS"insufficient but necessary part of a condition which is itself unnecessary but sufficient for the result" (Mackie 1976:62)

我舉個書上的例子哦..oxygen + dry paper + a spark = combustion前三項都是combustion 的充分條件, 但其中之一的dry paper卻不是combustion的必要條件.

The point is that there may well be alternative sets ofconditions, each of which is sufficient to bring about the event. None ofthere is necessary because the other sets would do as well.

可能對你來說不是腦內激盪吧...但對我來說是. 我花了一番功夫才弄懂的.