Appeal to the stone (argumentum ad lapidem)  is a logical fallacy where someone dismisses  

an argument or claim as absurd without providing  evidence or reasoning to support the dismissal.

It avoids debate by simply rejecting the  claim as unworthy of serious consideration. 

Every day Example: Imagine a situation in a  

school where a student proposes a new method  for organizing the library books by color to  

make it more visually appealing and possibly  easier for young students to find books. 

The librarian, without considering the  potential benefits or logistics of the idea,  

dismissively says, “That's the silliest  thing I've ever heard,” and moves on. 

While the librarian might be right to reject  the idea and might have valid argument against  

the idea, he did not actually present his  argument, this is an appeal to the stone  

because it rejects the proposal as absurd  without explaining why he thinks it is absurd.