I will show, in the next place, how Socrates' friends learnt to reason so well by frequenting his conversation. He held that they who perfectly understand the nature of things can explain themselves very well concerning them, but that a man who has not that knowledge often deceives himself and others likewise. He therefore perpetually conferred with his friends without ever being weary of that exercise. It would be very difficult to relate how he defined every particular thing. I will therefore mention only what I think sufficient to show what method he observed in reasoning. And, in the first place, let us see how he argues concerning piety. "Tell me," said he to Euthydemus, "what piety is?" "It is a very excellent thing," answered Euthydemus. "And who is a pious man?" said Socrates. "A man who serves the gods." "Is it lawful," added Socrates, "to serve the gods in what manner we please?" "By no means," said Euthydemus; "there are laws made for that purpose, which must be kept." "He, then, who keeps these laws will know how he ought to serve the gods?" "I think so." "And is it not true," continued Socrates, "that he who knows one way of serving the gods believes there is no better a way than his?" "That is certain." "And will he not be careful how he does otherwise?" "I believe he will." "He, then, who knows the laws that ought to be observed in the service of the gods, will serve them according to the laws?" "Without doubt." "But he who serves the gods as the laws direct, serves them as he ought?" "True, he does." "And he who serves the gods as he ought is pious?" "There can be no doubt of it." "Thus, then," said Socrates, "we have the true definition of a pious man: He who knows in what manner he ought to serve the gods?" "I think so," said Euthydemus.