Proving too much

An argument "proves too much" when you can just as easily or naturally extend it to prove false things as true things. For example, the argument "Nobody should engage in genetic engineering because Nazis" can just as easily be extended to say "Nobody should eat vegetables because Hitler ate vegetables", so the general rule proves too much.

See also:

• http://en.wikipedia.org/wiki/Proving_too_much
• http://slatestarcodex.com/2013/04/13/proving-too-much/