Full Idea
The closure principle forces us to regard Zula as knowing that what she is looking at is not a cleverly disguised mule, and yet she doesn't appear to have any supporting evidence for this knowledge.
Gist of Idea
We can have evidence for seeing a zebra, but no evidence for what is entailed by that
Source
Duncan Pritchard (Epistemological Disjunctivism [2012], 2.§3)
Book Reference
Pritchard,Duncan: 'Epistemological Disjunctivism' [OUP 2012], p.74
A Reaction
[Zula observes a zebra in the zoo] Entailment is a different type of justification from perception. If we add fallibilism to the mix, then fallibility can increase as we pursue a string of entailments. But proper logic, of course, should not be fallible.