Why does the author give the example of Socrates' cross examination of his accuser?

Directions: Answer the given question based on the following passage:

It needs but the simple statement of the nature of cross-examination to demonstrate its indispensable character in all trials of questions of fact. No cause reaches the stage of litigation unless there are two sides to it. If the witnesses on one side deny or qualify the statements made by those on the other, which side is telling the truth? Not necessarily which side is offering perjured testimony,--there is far less intentional perjury in the courts than the inexperienced would believe,--but which side is honestly mistaken?--for, on the other hand, evidence itself is far less trustworthy than the public usually realizes. Which side of the opinions are warped by prejudice or blinded by ignorance? Which side has had the power or opportunity for correct observation? How shall we tell and make it apparent to a jury of disinterested men who are to decide between the litigants? Obviously, by means of cross-examination.
If all witnesses had the honesty and intelligence to come forward and scrupulously follow the letter as well as the spirit of the oath, "to tell the truth, the whole truth, and nothing but the truth," and if all advocates on either side had the necessary experience, combined with honesty and intelligence, and were similarly sworn to develop the whole truth and nothing but the truth, of course there would be no occasion for cross-examination, and the occupation of the cross-examiner would be gone. But as yet no substitute has ever been found for cross-examination as a means of separating truth from falsehood, and of reducing exaggerated statements to their true dimensions.
To this day, the account given by Plato of Socrates’ cross-examination of his accuser,
Miletus, while defending himself against the capital charge of corrupting the youth of Athens, may be quoted as a masterpiece in the art of cross-questioning.
Cross-examination is generally considered to be the most difficult branch of the multifarious duties of the advocate. Success in the art, as some- one has said, comes more often to the happy possessor of a genius for it. Great lawyers have often failed lamentably in it, while marvelous success has crowned the efforts of those who might otherwise have been regarded as of a mediocre grade in the profession. Yet personal experience and the emulation of others trained in the art are the surest means of obtaining proficiency in this all-important pre-requisite of a competent trial lawyer.
It requires the greatest ingenuity; a habit of logical thought; clearness of perception in general; infinite patience and self-control; power to read men's minds intuitively, to judge of their characters by their faces, appreciate their motives; ability to act with force and precision; a masterful knowledge of the subject-matter itself; an extreme caution; and, above all, the instinct to discover the weak point in the witness under examination.