But Intuitionalism has further arguments for the doubter.
From the Greek sophists they borrowed ingenious ways of playing off one duty against another, or duty in general against self-interest - leaving the doubter in the alternative of neglecting the one and being a knave, or neglecting the other and being a fool.
Illegitimate doubt is the uncertainty of the doubter as to whether he has examined the whole of the evidence.
In order to lay bare the ground of certainty he raises the universal doubt, and, although, following Augustine,2 he finds its limit in the thought of the doubter, this of itself is not enough.
Later, doubter Susan is driven through an area to avoid traffic (with directions given to her by Kris).