The dialogues written during this period are presentations of the doctrine of Socrates and do not contain the constructive theory of Plato. They are concerned either with Socratic subjects or with Socrates personally, and were written in part during Socrates’ life, in part directly after his death. (a) Dialogues written under the influence of Socrates: _Lysis_, concerning friendship; _Laches_, concerning courage; _Charmides_, concerning moderation. (b) Dialogues written in defense of Socrates: _Crito_, concerning Socrates’ fidelity to law; _Apology_, a general defense of Socrates; _Euthryphro_, concerning Socrates’ true piety. =2. Plato as Traveler= (399–387 B. C.). During this period Plato made one short and two long journeys, and after each he returned to Athens. Upon the death of Socrates he went to Megara, where a former pupil of Socrates had a school. Upon this journey he was accompanied by other pupils of Socrates, who, as tradition has it, feared violence to themselves after the death of their master. Plato remained in Megara but a short time, and soon returned to Athens. Immediately upon his return to Athens he went to Cyrene and Egypt, and was away from Athens about four years (until 395 B. C.). The Egyptian journey had little influence upon his thought, but must have stimulated his imagination. He then remained at Athens four years (395–391 B. C.), and during this time he taught a small circle and wrote his polemics against the Sophists. In 391 B. C. Plato made his first Italian journey――to Sicily and southern Italy. This marks the second critical point in his mental development. For at this time (1) he came under the influence of the Italian Pythagoreans, and (2) he attempted and failed in connection with Dion[27] and Dionysius to erect his ideal state in Syracuse. He was sold as a slave by Dionysius, redeemed by a friend, and returned to Athens in 387 B. C., having been away about four years. It is to be noted that Democritus and Plato were wide travelers, considering the difficulties of locomotion of the time. Both Democritus and Plato went to Egypt, and Democritus spent several years in Asia Minor (see p. 107). The dialogues written during this period may be divided into (a) the group of polemics against the Sophists, and (b) the _Meno_. (a) The polemics against the Sophists (written between his return from Egypt in 395 B. C. and his first Italian journey in 391 B. C.). They are an attempt to present a solid front against the Sophists, and to show the weakness of the Sophistic doctrines. These polemical dialogues are: _Protagoras_, a criticism of the Sophistic assumption that virtue is teachable, because that assumption is incompatible with the Sophistic fundamental principle; _Gorgias_, showing how superficial the Sophistic rhetoric is when compared with true culture, which is the foundation of real statecraft;