What's the difference between perfectibilist and utopianist?

Perfectibilist

Definition:

• (n.) A perfectionist. See also Illuminati, 2.

Example Sentences:

Utopianist

Definition:

• (n.) An Utopian; an optimist.

Example Sentences:

• (1) The phrase itself has sparked a rhetorical battle between techno-utopianists and postmodern flâneurs: should the city be an optimised panopticon, or a melting pot of cultures and ideas?