In Greek city-states Metics (metoikoi), i.e. foreign residents, had come to obtain a definite status distinguishing them from other foreigners and giving them a recognized place in the community. Metics were found in many Greek city-states, but those of Athens were best known and played a very important part in the economic life of Athens. The old hostility against foreigners might have survived in the aristocratic city-states in which the labour was regarded as an inferior function, but it had disappeared from Athens as she became richer in trade and industry. The general opinion was expressed by Aristophanes in a striking simile: as good bread is made of flour and bran, the thriving city mixes pure citizens and solid Metics. In the fifth and the fourth centuries B. C, so many foreigners from almost all parts of the world established themselves in Athens that the non-Greek factors among her population increased more and more. As a result, there was formed in Greece in this period a kind of international nation which prepared the way, chiefly in economic interests but also in the domain of ideas and in the very framework of the Polis, towards the cosmopolitanism of the Hellenistic period.