On the Sophists
(30) In reply let me first say that I have expressed my views as I have, not because I altogether contemn the ability to write, but because I esteem it of lesser worth than extemporaneous speaking, and am of opinion that one should bestow the greatest pains upon the practice of speaking. Secondly, I am myself employing the written word, not because I especially pride myself therein, but that I may reveal to those who plume themselves on the ability to write that with a trivial expenditure of effort I myself shall be able to eclipse and destroy their discourses.
(31) Furthermore, I am now essaying the written word because of the display orations which are delivered to the crowd. My customary listeners I bid test me by that usual standard whenever I am able to speak opportunely and felicitously on any subject proposed. To those, however, who only now at last have come to hear me (never once having heard me previously) I am attempting to give an example of my written discourse. The latter are accustomed to hear the set speeches of the rhetors and, if I spoke extemporaneously, they might fail to estimate my ability at its real worth.
(32) Apart from these considerations, it is possible, from written discourses, to see the clearest evidence of the progress which it is fitting that there should be in thinking; for it is not easily discernible whether my extemporaneous speeches are now superior to those I formerly delivered, as it is difficult to remember speeches spoken in times gone by. Looking into the written word, however, just as in a mirror, one can easily behold the advance of intelligence. Finally, since I am desirous of leaving behind a memorial of myself, and am humoring my ambition, I am committing this speech to writing.
(33) It must distinctly be understood that I am not encouraging careless speaking when I say that I esteem the ability to speak extemporaneously more highly than the written word. My contention is that the orator must prepare himself in advance in ideas and their arrangement, but that the verbal elaboration should be extemporaneous; this extemporaneous verbal exposition, in its timeliness, is of greater value to the orator than the exact technical finish of the written discourse.
(34) In conclusion, then, whoever wishes to become a masterly speaker rather than a mediocer writer, whoever is desirous of being a master of occasions rather than of accurate diction, whoever is zealous to gain the goodwill of his auditor as an ally rather than his ill-will as an enemy, nay, more, whoever desires his mind to be untrammeled, his memory ready, and his lapses of memory unobserved, whoever has his heart set upon the acquisition of a power of speaking which will be of adequate service in the needs of daily life, this man, I say, with good reason, would make the practice, at every time and on every occasion, of extemporaneous speaking his constant concern. On the other hand, should he study written composition for amusement and as a pastime, he would be deemed by the wise to be the possessor of wisdom.