This note investigates the possibility of converses of the Weyl theorems that
two conformally related metrics on a manifold have the same Weyl conformal
tensor and that two projectively related connections on a manifold have the
same Weyl projective tensor. It shows that, in all relevant cases,
counterexamples to each of Weyl?s theorems exist except for his conformal
theorem in the 4-dimensional, positive definite case, where the converse
actually holds. This (conformal) 4-dimensional problem is then solved
completely for the other possible signatures.