Logical fallacies (3) - 28 September 2009 |
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The fact that an argument is illogical doesn’t mean that its conclusion will necessarily be wrong (see ‘the fallacy fallacy’, no 30, below). An obvious point to remember during disagreements (especially theological disagreements?). People can have the right answer for all sorts of wrong reasons.
And speaking of wrong reasons, here are a few more of them.
21. Fallacy of complex cause. One part of a cause is treated as if it were the sufficient cause.
What you need to sail around the world is determination.
What a healthy church needs is a focus on evangelism.
22. Fallacy of insignificant cause. An insignificant part of a cause is treated as if it were the sufficient cause.
What you need to sail around the world is a hat.
What a healthy church needs is a cool website.
23. Fallacy of reversed causality. The relationship between cause and effect is reversed.
An early symptom of scurvy is the inability to digest citrus fruit.
I’ll start praying when I have a bit more spare time to fit it in.
24. Fallacy of unrelated cause. Locating the cause of a phenomenon in an entirely unrelated factor.
As soon as we started providing decaffeinated tea and coffee after church, the stock market collapsed, therefore…
25. Fallacy of weak correlation. Locating the cause of a phenomenon in an effect which is related, but not strongly.
As soon as we started providing proper filter coffee after our services, the congregation began to grow rapidly in maturity.
Question: How do you determine (a) which other causes may be involved, and (b) the importance of their respective contributions?
26. Fallacy of equivocation. Ignoring the fact that a word or phrase is being used in two different senses.
Modern theologians deny the authority of Scripture, theologian X is a modern theologian, therefore…
Pete believes on the basis of 2 Peter 2:1 that the ‘elect’ spoken of in 1 Peter 1:1 can fall away, therefore he denies that the ‘elect’ predestined by God from eternity are all finally saved.
27. Affirming the consequent. Affirming a proposition on the basis that a consequence of that proposition is true. Formally: (1) if p then q; (2) q; (3) therefore p. Like this: (1) If it rains (p) the picnic will be cancelled (q); (2) the picnic is cancelled (q); (3) therefore it’s raining (p). The reason this fails is that the consequence q may have other sufficient causes.
If Jesus could return at any moment (p), then we’d need to be really serious about evangelism (q). Since we know that we should be really serious about evangelism (q), it must therefore be true that Jesus could return at any moment (p).
28. Denying the antecedent. Denying a proposition on the basis that a cause (antecedent) of that proposition is false. Formally: (1) if p then q; (2) not-p; (3) therefore not-q. Like this: (1) If it rains (p) the picnic will be cancelled (q); (2) it’s not raining (not-p); (3) therefore the picnic will not be cancelled (not-q). Again, this reason fails because the consequence q may have other sufficient causes.
If Jesus could return at any moment (p), then we’d need to be really serious about evangelism (q). So if you didn’t believe that Jesus could return at any moment (not-p), then you’d just give up on evangelism (not-q).
You’d be more likely to hear this fallacy in a form like this: ‘People who don’t think that Jesus is coming back soon will tend to give up on evangelism.’
Question: what other reasons might be given for taking evangelism seriously?
29. Humour and ridicule. Deploying humour or ridicule inappropriately, or to avoid the issue, or to cast unwarranted aspersions, or in the absence of a reasoned argument.
You can never take Liberals seriously – they never know what to say if someone asks, ‘What must I do to be saved?’
Question: is humour or ridicule ever appropriate in theological argument? Biblical examples?
30. The fallacy fallacy. Maintaining a position on the grounds that you have heard the opposite position maintained on the basis of flawed logic.
The easiest way to see this is to note that none of the (fallacious) arguments in this list implies anything (necessarily) about the conclusions to those arguments. It might, for example, be true that theologian X does deny the authority of Scripture (no. 26). Or it might be false. You can’t tell either way from the argument itself. And it’s therefore illogical to reject a view merely because illogical arguments have been adduced in its support.
31. Oversimplification. Simplifying a situation or argument to an inaccurate or absurd degree.
Catholics believe in the sacraments, whereas Protestants believe in the word.
Keeping the Sabbath is legalism.
The New Perspective denies the doctrine of justification by faith.
To claim that extra-biblical information can help us to interpret the Bible undermines the perspicuity (clarity) of Scripture.
32. Genetic fallacy. Attacking an idea on the grounds that its source or supposed motivation is unworthy in some way.
He would believe that – he’s a liberal.
Of course she believes in remarriage after divorce – she’s a divorcee.
Tom Weinandy? But he’s a Roman Catholic!
33. Guilt by association. Attempting to discredit a conclusion by suggesting (not proving) a connection with other people, theological positions etc. that all parties agree (or, according to the speaker, ought to agree) are bad in some way.
I don’t like the idea that the Gospels were composed from pre-existing fragments of oral and written tradition – that’s the sort of thing Liberals believe.
Belief in predestination leads to hyper-Calvinism, and undermines enthusiasm for evangelism.
34. Inconsistency. Arguing for a conclusion whilst simultaneously maintaining another position that is logically incompatible with it.
God is sovereign, but he doesn’t constrain our choices.
I do believe in penal substitutionary atonement; I just don’t believe that God is personally angry at sin.
35. Stolen concept fallacy. Arguing for a conclusion whilst simultaneously attacking another position on which it logically depends.
I don’t believe in God; we should all just respect each other.
36. Nothing but objections. Continually raising objections, or merely hinting at their existence, as a means of avoiding the issue.
Penal substitutionary atonement raises all kinds of problematic implications for the doctrine of the Trinity.
37. Red herring. Attempting to avoid engaging with an argument by raising an unrelated subject.
[Example overheard during a conversation about why it is OK to attend a Roman Catholic Mass:] Well, plenty of stuff that goes on in some evangelical churches is pretty unhelpful too!
38. Tu quoque (lit. ‘you too’). Arguing against someone on the grounds that their position, like yours, is also problematic.
I know my reading of v. 1 doesn’t square with v. 2, but your reading doesn’t square with v. 3.
39. Occam’s razor fallacy. Arguing in favour of a conclusion on the grounds of its (alleged) simplicity.
The interpretation of Revelation 13 / Revelation 17 / Daniel 7–12 has been clouded by endless discussions of the identity of the kingdoms or individuals to whom the different beasts correspond. It becomes much simpler, however, once we realise that they all refer in a general sense to ungodly human political power.
40. Fallacy of the beard. Rejecting a concept or argument because of borderline cases that are difficult to adjudicate.
How many hairs do you need before you’ve got a beard? One? Two? Ten? Seventy-three? Well, if you can’t tell me, then I’m afraid the notion of ‘a beard’ ceases to have much relevance.
How many packets of crisps per day counts as ‘greedy’? One? Two? Ten? Seventy-three? Well, if you can’t tell me, then I’m afraid the notion of ‘greed’ ceases to have much relevance.
You run into all sorts of problems if you think the OT law teaches us about the Christian life – remember all that stuff about boiling goats in their mother’s milk?
41. Paradigm or cultural fallacy. Taking one’s own system of thought or culture as the standard by which all others must be judged.
One ought to wear a tie to church; anything less is a gesture of disrespect to the Almighty.
But that contravenes the Westminster Standards!
But that’s not what Pastor Jim always told me!
42. Fallacy of the undistributed middle (‘All that glitters is not gold’).
Gold glitters, John’s eyes glitter, therefore John’s eyes are gold.
Evangelicals really believe in preaching, and John believes in preaching, so John’s an evangelical.
43. Ad antiquitatem (lit. ‘from oldness’?). Assuming that something must be right because it has been believed for a long time, or because it was believed a long time ago.
None of the Church Fathers denied a literal 6-day creation.
Question: does the fact that an idea has a good historical pedigree have any relevance? Why / why not?
44. Ad Novitatem (lit. ‘from newness’?). Opposite of 43: Assuming that something must be right because it is a recent idea.
No serious modern scientists believe in a literal 6-day creation.
Posted by Steve Jeffery · Topics: Guided Reading Course, Minister's Blog