However, in this culture, in this Western culture we live in, in order to make effective arguments, we must "speak in their language" so to speak. ÃƒÆ’Ã¢â‚¬Å¡Ãƒâ€š Thus, insults and tough lines are unnecessary, although tempting, considering the culture we come from, and I sometimes fall into this as well.
Since I enjoy studying rhetoric as an art form I thought I'd throw in a few of my personal observations that have come from reading history's great propagandists from Marcus Tullius Cicero and Caesar Augustus to Winston Churchill and Joseph Goebbels.
The essentials dont change from culture to culture, only the details. When dealing with the masses, mindless slogans and pure emotionalism have always worked best. You dont get volunteers for an army by logically explaining the necessity of the conflict at hand, rather you get volunteers by raising the flag and whipping up feelings of nationalistic or religious pride.
In intellectual circles people want to have their egos stroked, so they demand you mask the nationalistic or religious pride with the skills of rhetoric, they will then evaluate what rhetoric is most 'intellectually' (read emotionally) stimulating. Because of these egos they dont like anyone to be called stupid outright, that's beneath them, instead you must dismiss the other person's argument and imply in your debate that only a complete idiot would hold such an absurd posistion, if you win the argument you have effectively not only called the other person an idiot but you have also demonstrated that they are an idiot.
So while the technicalities may differ when addressing the masses or the intellectual elite, the goals and overall strategies are the same, discredit your enemies and destroy them, the more complete their destruction the greater your victory. But in both cases, play by the rules, a violation of the established 'rules' of the forum is the easiest thing for your enemy to exploit and unless you can discover a rule violation of your enemy and blow it out of proportion, you're in deep trouble, regardless of how good your arguments are.
So, yes, by all means call your enemy stupid, that's essentially the goal in a debate, but also abide by the rules of the forum; if you can evolve and expand the rules to make your propaganda more effective, great, go for it...but don't openly break the rules or the backlash will undermine your posistion.
A great example of this is with Caesar Augustus in establishing the posistion of the Emperor, in doing this he exploited the legacy of his uncle and adopted father, Julius Caesar, who he had declared a son of the gods by the Senate, implying his own divinity by extension, but never actually stating such a thing, which would not have been received well by the republican Romans. Also to this extent, he depicted himself barefoot, since Nudity was a symbol of divinity this depicting of himself barefoot again implied his divinity, but he was not entirely nude in teh statues, he didn't openly claim divinity. This move pushed the boundaries of what was acceptable and ultimately helped Caesar Augustus strengthen his posistion for a long and prosperous reign. Some of his successors, on the other hand, were not quite so intelligent...Caligula would later openly declare his divinity in doing so he lost much suppord and soon thereafter be assassinated. Domitian later did not learn from this example, openly declared himself divine, and suffered a similar fate. The great propagandist knew just how far he could push the issue, went that far and no further, those less skilled and capable foolishly rushed out and had their heads chopped off.