Remember that [scientific thought] is the guide of action; that the truth which it arrives at is not that which we can ideally contemplate without error, but that which we may act upon without fear; and you cannot fail to see that scientific thought is not an accompaniment or condition of human progress, but human progress itself.
William Kingdon Clifford, Leslie Stephen, Frederick Pollock (2011). “Lectures and Essays”, p.157, Cambridge University Press