Final answer:
Antonius, as referenced in Cicero's De Oratore, highlights the importance of body language and controlled physical presence for an orator, advising against excessive theatrics in favor of dignified and complementary gestures to speech.
Step-by-step explanation:
According to Quintilian's Institutes of Oratory, the ideal orator is one who commands not only their speech but also their physical presence. Antonius from De Oratore, as mentioned by Cicero, emphasizes the importance of the orator's body language being more expressive than the hands, advocating for restraint in movement and a dignified poise of the upper body. In contrast to some of the flamboyant styles of the time, such as thigh-slapping as a sign of indignation, the ideal orator should avoid overt theatrics and instead use controlled gestures that complement their spoken words, enhancing their public speaking abilities.