Indifference to truth can not, in and by itself, produce erroneous belief
 John Stuart Mill, A System Of Logic, Ratiocinative And Inductive (1843). copy citation

Context

“they do not act directly, but by means of the intellectual causes; to which they bear the same relation that the circumstances called, in the theory of medicine, predisposing causes, bear to exciting causes. Indifference to truth can not, in and by itself, produce erroneous belief; it operates by preventing the mind from collecting the proper evidences, or from applying to them the test of a legitimate and rigid induction; by which omission it is exposed unprotected to the influence of any species of apparent evidence which offers itself spontaneously, or which is elicited by that smaller quantity of trouble which the mind may be willing to take.” source