the following, which is inductively forceful but unsound due to the falsity of P2:

P1) Generally people who make a will live longer than those who don't.

P2) Whenever one event (Y) occurs after another event (X), Y

is caused by X P3) Living longer (not dying) occurs after making a will.

C) (Probably) Making a will causes people to live longer.

The post hoc ergo propter hoc fallacy is frequently committed in public discourse when arguers are attempting to persuade people of the merits of a policy or piece of legislation. Thus tougher sentencing policies might be fallaciously inferred to be the cause of a drop in the crime rate or a teachers' pay increase to be the cause of better examination marks in schools. Where the second event is alleged to be causally linked to the first solely on the basis that it occurred after the first, the argument is almost definitely fallacious. This is not to say that tougher sentencing, say, couldn't be a cause of a drop in the crime rate, it's just that we need to be given stronger reasons to accept the causal claim than simply the fact that one event occurred before the other.

Fallacy of mistaking correlation for cause

Whereas the fallacy of post hoc ergo propter hoc occurs because the temporal priority of one event over another is taken as sufficient to establish a causal relationship between those events, this fallacy is committed when the fact that one type of event or state of affairs is always or usually found in conjunction with another type, is mistakenly taken to be sufficient to establish that events or states of affairs of the one type cause the other. In summary, the fallacy is committed when a statistical correlation is assumed, without any further justification, to establish a causal relation. So, for instance, someone who argues,

You only have to look at the statistics to see that poverty is the obvious cause of educational under-achievement. Eighty per cent of those who leave school with no qualifications come from homes whose income is at least 50 per cent below the average.

Rhetorical ploys and fallacies

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