what if...

[Beautus]

Pinocchio said "My nose will grow"

if it did then he was telling the truth.
if it didn't then he was lying  

[JP McGraw]

Perhaps it would make an attempt to grow, yet any piece of his nose that was further out than the tip of his nose had been would rot and fall away.

Yeah, that's my theory.  

[Beautus]

JP McGraw

Perhaps it would make an attempt to grow, yet any piece of his nose that was further out than the tip of his nose had been would rot and fall away.

Yeah, that's my theory.

i think its just that Pinocchio is omnipotent  

[Slytherin Lord]

If it grows that means he is telling a lie but that would mean iff he says "my nose will grow" and his nose does grow then it will mean he told a lie but at the same time the truth causing his nose to grow then shrink and grow again and shrink again, etc...