In all this we have a definite recognition of the fact that knowledge progresses.  Bacon did not come into close quarters with the history of civilisation, but he has thrown out some observations which amount to a rough synthesis. [Footnote:  Advancement, ii. 1, 6; Nov.  Org. i. 78, 79, 85.] Like Bodin, he divided, history into three periods—­(1) the antiquities of the world; (2) the middle part of time which comprised two sections, the Greek and the Roman; (3) “modern history,” which included what we now call the Middle Ages.  In this sequence three particular epochs stand out as fertile in science and favourable to progress—­the Greek, the Roman, and our own—­“and scarcely two centuries can with justice be assigned to each.”  The other periods of time are deserts, so far as philosophy and science are concerned.  Rome and Greece are “two exemplar States of the world for arms, learning, moral virtue, policy, and laws.”  But even in those two great epochs little progress was made in natural philosophy.  For in Greece moral and political speculation absorbed men’s minds; in Rome, meditation and labour were wasted on moral philosophy, and the greatest intellects were devoted to civil affairs.  Afterwards, in the third period, the study of theology was the chief occupation of the Western European nations.  It was actually in the earliest period that the most useful discoveries for the comfort of human life were made, “so that, to say the truth, when contemplation and doctrinal science began, the discovery of useful works ceased.”

So much for the past history of mankind, during which many things conspired to make progress in the subjugation of nature slow, fitful, and fortuitous.  What of the future?  Bacon’s answer is:  if the errors of the past are understood and avoided there is every hope of steady progress in the modern age.

But it might be asked.  Is there not something in the constitution of things which determines epochs of stagnation and vigour, some force against which man’s understanding and will are impotent?  Is it not true that in the revolutions of ages there are floods and ebbs of the sciences, which flourish now and then decline, and that when they have reached a certain point they can proceed no further?  This doctrine of Returns or ricorsi [Footnote:  Bodin’s conversiones.] is denounced by Bacon as the greatest obstacle to the advancement of knowledge, creating, as it does, diffidence or despair.  He does not formally refute it, but he marshals the reasons for an optimistic view, and these reasons supply the disproof The facts on which the fatalistic doctrine of Returns is based can be explained without resorting to any mysterious law. [Footnote:  Nov.  Org. i. 92 sqq.] Progress has not been steady or continuous on account of the prejudices and errors which hindered men from setting to work in the right way.  The difficulties in advancing did not arise from things which are not in our power; they were due to the human understanding, which wasted time and labour on improper objects.  “In proportion as the errors which have been committed impeded the past, so do they afford reason to hope for the future.”