A well known skeptical paradox rests on the claim that we lack warrant to believe that we are not brains in a vat (BIVs). The argument for that claim is the apparent impossibility of any evidence or argument that we are not BIVs. Many contemporary philosophers resist this argument by insisting that we have a sort of warrant for believing that we are not BIVs that does not require having any evidence or argument. I call this view ‘New Rationalism’. I argue that New Rationalists are committed to there being some evidence or argument for believing that we are not BIVs anyway. Therefore, New Rationalism, since its appeal is that it purportedly avoids the problematic commitment to such evidence or argument, undermines its own appeal. We cannot avoid the difficult work of coming up with evidence or argument by positing some permissive sort of warrant.