Equally important for him is that human rationality has as its setting a maximally rational universe. His confidence in the fundamental orderliness of all things is expressed in frequent references to Zeus or “the god” as the designer and administrator of the universe.
This also explains why Smith also used the "invisible hand" argument decades before he wrote the Wealth of Nations.
1The life of Adam Smith / Ian Simpson Ross.
Oxford : Clarendon Press ; New York : Oxford University Press, 1995.