What is "apagoge"

Apagoge \Ap`a*go"ge\, n. [Gr. ? a leading away, fr. ? to lead away; ? from + ? to lead.] (Logic) An indirect argument which proves a thing by showing the impossibility or absurdity of the contrary.

n. (context logic English) An indirect argument which proves a thing by showing the impossibility or absurdity of the contrary.