It must be clearly understood that the whole of this secondary education was purely voluntary. The parent need not send his lad to hear any teaching of the sort: the poorer classes certainly would not. The richer parents could choose what subjects they or their sons preferred: rhetoric or literature, geography or mathematics――it was all one to the State. Teachers came and went: few stayed in Athens long. Their pupils had either to follow them abroad, as Isokrates went to Gorgias in Thessaly, or wait for their next visit. It was only the schools of Isokrates, of the great philosophers, and of a few speech-writers like Lusias and Isaios, that had any permanence in Athens. Isokrates himself had taught in Chios for a time: Plato was more than once in Sicily, and his school had to do without him in his absence. There is a peculiar fluidity about secondary education in Hellas: the teachers are always on the move. Endowed buildings for them there were none: they taught in their own houses and gardens, or in those of rich hosts, or in school-rooms borrowed for the occasion, or in public resorts like the gymnasia, or even in the streets. Consistent or continuous instruction was the exception: the Sophists proper gave it only to a few. The average lad at this time naturally acquired a wide and superficial knowledge of a great number of subjects, just the amount of knowledge which is such a dangerous thing. The lads became Jacks-of-all-trades: Plato, struck with the educational error of wide superficiality, wrote the _Republic_ as a counterblast, preaching “One man, one trade.” This protest is largely directed against the specious superficiality of the Sophists’ teaching. Consequently, secondary education fell into two halves, the fluid teaching of the wandering Sophists and the continuous teaching of the more stationary schools of Plato and Isokrates. It will be convenient to accept this division, and take the fluid half first. In subjects, the two must overlap one another: the Sophists taught logic as much as Plato, rhetoric as much as Isokrates, and universal information of very much the same range as Aristotle. But the method was different, just because as a rule the Sophist was here to-day and gone to-morrow, while the stationary teachers taught the same pupils for several years together and could study their particular idiosyncrasies, and the value of education depends very largely on the teacher’s understanding of, and sympathy with, the individual boys whom he teaches. It is of interest to trace the development of the term Sophia and of the Sophists who professed it.