Shifting the burden of proof 149
There are muscular exercises which you should practise every
day in front of a mirror, and which assist the mental contortions
needed to shift ground rapidly.
Yes, I walked through the green line, customs officer, and I can explain
that extra bottle of scotch.
(Does anyone spot the slight tremor in his feet?)Shifting the burden of proof
Shifting the burden of proof is a specialized form of the argu-
mentum ad ignorantiam. It consists of putting forward an assert-
ion without justification, on the basis that the audience must
disprove it if it is to be rejected.
Normally we take it that the new position must have sup-
porting evidence or reason adduced in its favour by the person
who introduces it. When we are required instead to produce
arguments against it, he commits the fallacy of shifting the
burden of proof.
'Schoolchildren should be given a major say in the hiring of their
teachers. '
'Why should they?'
'Give me one good reason why they should not. '
(It always looks more reasonable than it is. You could equally ask that
the janitor, the dinner-ladies and the local bookie be given a say.
Come to think of it, they might do a better job.)It is the proposal itself which has to be justified, not the
resistance to it. The source of the fallacy is the implicit pre-
sumption that something is acceptable unless it is proved