The Sleepwalkers: A History of Man's Changing Vision of the Universe

by Arthur Koestler

After invoking Augustine’s authority once more, Galileo draws a distinction between scientific propositions which are ‘soundly demonstrated’ (i.e. proven) and others which are ‘merely stated’. If propositions of the first kind contradict the apparent meaning of passages in the Bible, then, according to theological practice, the meaning of these passages must be reinterpreted – as was done, for instance, with regard to the spherical shape of the earth. So far he has stated the attitude of the Church correctly; but he continues: ‘And as to the propositions which are stated but not rigorously demonstrated, anything contrary to the Bible involved by them must be held undoubtedly false and should be proved so by every possible means.’16