Most books of the warfare-of-science sort are built more or less on the same plan. Let us take the case of the figure of the earth for an example. They often treat it in the following order: The primitive conception, that of a flat earth; early scientific ideas of its sphericity; opposition of the early church; evolution of a sacred theory drawn from the Bible; its influence on christian thought; survival of the idea of a spherical earth; contrast of the theological and scientific spirit; last outbursts of theological hostility; retreat of the church; final triumph of science over theology. Or, more briefly, their treatment may often be summarized thus: Science always right; theology always interfering; glory to us who have done away with superstition!
The real conflict of the ages has been between enlightenment and ignorance. Sometimes the battle has been in the field of theology; sometimes it has been in the field of science. The warfare has nearly always been between religion and heresy; or between science and pseudo-science; occasionally, but not very often, between religion and pseudo (or it may sometimes be true) science. Usually, however, the fields were plainly marked off. The theologians of any one epoch treated theological questions and only those. They were not even interested in scientific questions, as such. Men of science, before the time of Galileo and Bruno, did not meddle with religion. Each class kept to its own sphere.
But let us return to the question of the figure of the earth. Untutored man believed the earth to be flat; the sky to hang above it like a canopy; the stars to be fixed to the canopy (or to hang from it as the Arabs taught); the canopy to move from rising to setting, from east to west. Now, this was an entirely scientific theory. It accounted satisfactorily for every fact known to untutored man. A theory is perfect when a future phenomenon can be predicted beforehand as accurately as it can subsequently be observed. This was then, at the time, a perfect theory; it needed no apologies. Aristarchus and other Greeks saw that the observed phenomena (rising and setting of the stars) could be as well explained by a spherical earth that turned on its axis—as well, but no better. They did not know which theory was true. They had no means of deciding the point.
A matter of importance must be here alluded to. Long centuries of experience have taught us that there is one and only one solution to a scientific problem. We call such a unique solution a 'theory.' Anything less definite is a provisional 'hypothesis.' Now, the theories of the ancients were generally held by them primarily as hypotheses. Their whole attitude towards certainty was, in physical science, entirely different from ours. It has required all the centuries to teach us our lesson of implicit trust in scientific methods. Our trust is, in fact, in methods, not, primarily, in results. In general, a physical theory attributed to one of the ancients was held by him as we hold a hypothesis. It