resemblance is nothing but our feeling of resemblance
 John Stuart Mill, A System Of Logic, Ratiocinative And Inductive (1843). copy citation

Context

“These, not being grounded on any fact or phenomenon distinct from the related objects themselves, do not admit of the same kind of analysis. But these relations, though not, like other relations, grounded on states of consciousness, are themselves states of consciousness: resemblance is nothing but our feeling of resemblance; succession is nothing but our feeling of succession. Or, if this be disputed (and we can not, without transgressing the bounds of our science, discuss it here) , at least our knowledge of these relations, and even our possibility of knowledge, is confined to those which subsist between sensations, or other states of consciousness;” source