John Frame, at TGC’s blog, is clipped to say these important things about the almost always fallacious use of the slippery slope. First, he defines it well:
A true and valid reductio must be distinguished from its fallacious imitators, one of which is the ‘slippery slope’ argument. A slippery slope argument goes like this.
‘If you take position A, you run the risk of taking position B;
position B is wrong,
therefore A is also wrong.’
Then he says what it really is all about — fear:
Thus the slippery slope argument appeals to fear—to our fear of taking undue risks and to our fear of being linked with people (such as liberals), disapproved of in our circles, lest we incur guilt by association.
Then he contends most historical examples are precisely not slippery slopes:
In general, they prove nothing.
Usually, they do not rest on a sufficient statistical sample to establish even probable conclusions.
And they ignore the complexities of historical causation.
He all but said Wayne Grudem et all ought to stop. I will.
The best example of slippery slope in the Bible is the Judaizing Christians’ accusations against the apostle Paul’s life of freedom in the Spirit. Scared the hooie out of them. So they jumped to fear-based conclusions.