Each of these predominated in its turn, though not to the exclusion of others, the sophistry of culture beginning about 447, and leading to the sophistry of eristic, and the sophistry of rhetoric taking root in central Greece about 427, and merging in the sophistry of politics.
Finally, the practice of rhetoric and eristic, which presently became prominent in sophistical teaching, had, or at any rate seemed to have, a mischievous effect upon conduct; and the charge of seeking, whether in exposition or in debate, not truth but victory - which charge was impressively urged against the sophists by Plato - grew into an accusation of holding and teaching immoral and unsocial doctrines, and in our own day has been the subject of eager controversy.
Finding in the cultivation of " virtue " or " excellence " a substitute for the pursuit of scientific truth, and in disputation the sole means by which " virtue " or " excellence " could be attained, he resembled at once the sophists of culture and the sophists of eristic. But, inasmuch as the " virtue " or " excellence " which he sought was that of the man rather than that of the official, while the disputation which he practised had for its aim, not victory, but the elimination of error, the differences which separated him from the sophists of culture and the sophists of eristic were only less considerable than the resemblances which he bore to both; and further, though his whole time and attention were bestowed upon the education of young Athenians, his theory of the relations of teacher and pupil differed from that of the recognized professors of education, inasmuch as the taking of fees seemed to him to entail a base surrender of the teacher's independence.
Again, as the Socratics - Plato himself, when he established himself at the Academy, being no exception - were, like their master, educators rather than philosophers, and in their teaching laid especial stress upon discussion, they, too, were doubtless regarded as sophists, not by Isocrates only, but by their contemporaries in general; and it may be conjectured that the disputatious tendencies of the Megarian school made it all the more difficult for Plato and others to secure a proper appreciation of the difference between dialectic, or discussion with a view to the discovery of truth, and eristic, or discussion with a view to victory.
There is less to be said for the teachers of rhetoric, politics and eristic, who, in limiting themselves each to a single subject - the rhetoricians proper or forensic rhetoricians to one branch of oratory, the politicians or political rhetoricians to another, and the eristics to disputation - ceased to be educators and became instructors.