Dedekind domains are
characterized among integral domains by the property that every ideal be a
projective module. The most naive dual characterization—that every homomorphic
image of R be an injective module—is false. In fact, a domain with this property
would have to be a field. An injectivity property that works, in the noetherian case, is
the property that every proper homomorphic image be a self-injective ring. The main
result of this note is: