Techniques in Persuasion from Antiquity
thecollector.com
thecollector.com
I'd also differentiate that from sales persuasion, or salary negotiation, among others, which is also a great skill but not the life-or-death, make-it-or-break-it moment when you need to out-argument a large room where each misstep may mean +/- X million bucks. The big leap of faith most investor or acquirers take into your business cannot be dealt with just plain excitement and the usual shenanigans, and ideally should, at least, be practiced beforehand and be well prepared. I've seen and suffered so much: enticing gifts as openers, missing decision-makers at key moments, delays, lawyers thrown in out of nowhere, the "higher authority" tactic, Socratic stances... Some people definitely flourish at the negotiation table. I don't.
Demosthenes’ speeches seem rather dull in translation (I’m sure I’d appreciate them more if I had any talent for Attic Greek), and if we’re honest they had little effect on Athenian fortunes until the Lamian War finally exhausted Macedon’s patience. But it’s definitely worth reading him alongside Aeschines for their lifelong rap battle.
Also, some effect is lost in the translation as well.
Cicero's letters were meant to be read, I suggest you try them. They kind of feel monotonous at times, but it's hard to ignore how good a writer he was.
Obviously we're missing a lot of Demosthenes and Aeschines too - the former's physical gestures, the latter's actorly delivery. You can kind of feel the way Demosthenes hammers his point home, the monotony has a point. It's just surprising when you first come across it - this is the purported height of oratory, and instead of soaring, it's incredibly functional.
In general, sure. But a manual on how to be persuasive doesn't seem like the place to do that weighing.