Heidegger affirmed traditional technology, but was opposed to science-based modern technology, in which everything (including man) is considered to be a mere "resource". This opposition was expressed in the form of deep questioning and a suspicion of superficial evaluation, because the true nature of things was often concealed, though disclosed at times. Ways in which engineers should question technology are proposed, highlighting some of the hazards and injustices associated with technology and also its subtle sociological and psychological influences. The demands of engineering ethics and the use of metaphor in design are other ways in which a narrowly rationalistic technological outlook can be confronted.