Full Idea
Thinking rationally is interpreting according to a scheme we cannot cast away.
Gist of Idea
Rationality is a scheme we cannot cast away
Source
Friedrich Nietzsche (Writings from Late Notebooks [1887], 05[22])
Book Reference
Nietzsche,Friedrich: 'Writings from the Late Notebooks', ed/tr. Bittner,Rüdiger [CUP 2003], p.110
A Reaction
We can turn the tables on this one: how could Nietzsche know that this is the case if he cannot criticise his own rationality? The brain is a truth machine, and truth is (mostly) vital for survival.