Most of us use the products of science-railway aeroplanes electricity, wireless and thousands of others - without thinking how they came into existence. We take them for granted, as if we entitled to them as a matter of right. We are very proud of the fact that we live in an advanced age and pride ourselves very advanced. Now, there is no doubt that our age is very different from previous ages and think it is perfectly correct to say that it is far more advanced. But it is a different thing from saying that we, as individuals or groups, are more advanced. It would be the height of absurdity to say that because an engine driver can run an engine and Plato or Socrates could not, the engine driver is more advanced than or is superior to, Plato or Socrates. But it would be perfectly correct to say that the engine itself is a more advanced method of locomotion than Plato's chariot was.