The point has been made a number of times, but it is worth repeating: as a general rule, the ANC and its alliance partners consistently refuse to argue on the facts, relying rather on character assassination and misdirection instead.

More particularly, whereas Thabo Mbeki and his acolytes often used quite complex logical fallacies and the manipulation of language to misdirect debate, Jacob Zuma and his confidants rely on more brutal ad hominem attacks, along with far less complicated and far more direct language.

Both are equally dishonest and both say something about the character of the relevant individual.

Briefly, here is a quick analysis of the latest such example.

University of South Africa rector, Barney Pityana, in a recent address to the Law Society of South Africa, warned against a Jacob Zuma presidency. He presented various pieces of evidence, in support of his argument. I will not set out all of them here, but by way of illustration here are three:

·He faces charges of corruption and fraud: "To many of us, Jacob Zuma, popularly elected by the branch delegates at Polokwane in December 2007, remains a flawed character in his moral conduct; he has been indicted for serious crimes that involve corruption and dishonesty."

·His policy positions are inconsistent: "We have seen the leader flip-flop on crucial matters of policy - the death penalty, silence when his supporters mount a savage and uninformed attack on the judges, ostensibly with his concurrence, the dance of back step on the reform of the labour market, and so on."

·He and his supporters have a disregard for SA's criminal justice system and the constitution: "That is the reason South Africans should be very concerned when the ANC Youth League confronts the Deputy President of the Constitutional Court about remarks he is reported to have made at a private function, and the sentiment about the integrity and independence of judges that is thrown up, the effect of which is clearly to intimidate the judiciary."

Evidence is the base on which any argument must be built; and that is exactly what Pityana did. He has a particular view of Jacob Zuma, a view which he presented and supported with evidence.

Now, that is not to say that view cannot be refuted. I happen to agree with it; but, if I was to play Devil's Advocate, I could refute each of those points with a counter-argument, also supported with evidence. I might argue for example, with regard to the first point, the charges were the result of a conspiracy, that there was evidence to support this - the fact that almost every other senior official implicated in the arms deal has been protected from prosecution - and that it is therefore unfair to make deductions about Zuma's moral character in this regard.

As it so happens, the evidence presented by Pityana is very strong, which make any defence all the more difficult and any counter-argument relatively weak. Nevertheless, you cannot properly refute the argument he presents without dealing, first and foremost, with his evidence.

But the reaction to Pityana's address, by those loyal to the ANC president, suggests an organisation which is simply out of its league when it comes to producing cogent arguments and analysis; or, alternatively, has chosen to embrace bullying and intellectual thuggery as its modus operandi, when attempting to deal with criticism.

Let's look at two such responses, by way of illustration.

First, the SACP's rather radical youth wing, the Young Communist League (YCL) - as fervent an opponent of Mbeki, as it is a supporter of Zuma. Here is its full response:

"The YCL notes the disrespectful and dastardly remarks made by the deplorable UNISA Vice-Chancellor Barney Pityana against the ANC President Jacob Zuma. This is a clear indication that the Vice-Chancellor is attacking the ANC President opportunistically to project his defeated political handlers in Polokwane as genuine and true leaders. As the YCL we do not doubt the leadership qualities of the ANC President and we will continue unapologetically to support him to lead the country in 2009. The Vice-Chancellor should desist from these unwarranted insults and focus on transforming UNISA by broadening access for the previously disadvantaged students especially for those from the working class and the poor background. It is regrettable that Pityana has a personal and political vendetta against the ANC President and he uses it in a malicious and opportunistic manner to settle cheap and factionalist political scores. It is our contention that Pityana is not a good political leader of note and his political career died in 1978. His contribution to the liberation struggle is politically empty since in exile he was in business of being a boarding academic and political demagogue tourist. The YCL believes that Pityana is nothing else, but a mere political mercenary seeking cheap political publicity. We urge the gutter Vice-Chancellor to desist from political gimmicks that insults and undermine the persons of ANC President."

The statement is loaded with personal attacks: "[Pityana's] political career died in 1978"; "[He is] a boarding academic and political demagogue tourist", "[He is] a mere political mercenary seeking cheap political publicity."

It accuses him of being malicious, opportunistic, harbouring a political vendetta, being disrespectful and dastardly and implies he is Mbeki's political lackey.

But nowhere, at no point, does it even begin to attempt to address the argument put forward by Pityana. In fact, so intellectually bereft of content is the statement that it doesn't even bother to provide evidence for the insults it hurls at him.

It is a classic example of playing the man and not the ball and of an ad hominem attack that tries to misdirect debate by focusing on the character of the author, rather than the content of the argument he presents.

But let's not read too much into this; it is after all the YCL, an organisation which - much like the ANCYL - has a longstanding record of hyperbole and over-the-top rhetoric. What about the ANC itself, surely it had a better, more considered response?

Not so. Its response came from staunch Zuma supporter and newly elected ANC secretary-general Gwede Mantashe. Mantashe's remarks were made off the cuff, so there is no full statement one can point to. Nevertheless, if the press's account is accurate, there is little material difference between what Mantashe and the YCL had to say.

According to The Times, Mantashe described Pityana's statements as "spurious" and a reflection of "intellectual bankruptcy". He said: "We saw the statement by Professor Barney Pityana. We describe them as spurious statements against the president of the ANC." Mantashe went on to argue that Pityana's statements were an indication that he was clinging to personalities and failing to view the ANC as a whole.

The Sowetan reported Mantashe as saying that Pityana's hatred for Zuma had made him "stagnate" and that he had failed to even recognise the reality that South Africa's perception about the new ANC president had already changed for the better. It also reported that he also accused Pityana of suffering from a syndrome of worshiping individuals within the ANC. He said this was, "the challenge that social scientists (like Pityana) sometimes faced - they failed to move with the times".

Once again, Pityana's character was attacked but, significantly, not his argument. He was labelled stagnant, intellectually bankrupt and accused of being out of touch and redundant, and, like the YCL, the implication was made that he was just acting as Mbeki's lackey.

But his argument? The facts he put forward? Not one of them was addressed, in any shape or form.

Just to illustrate how disingenuous the ANC and YCL's responses are, consider it had taken place in a court of law. Barney Pityana would have made his case, presented his evidence and, from that, drawn certain conclusions. In response, Zuma's team would have attacked Pityana's character in the manner outlined above, not refuting the facts or presenting contrary evidence. Thus - and unfortunately for Zuma, as the court is only interested in the facts - this would have been to his detriment and a failure to counter the evidence presented would inevitably have meant the court would have sided with Pityana.

And so it is for anyone able to distinguish a coherent argument from empty rhetoric.

Now, that is not to say that Pityana does not have a political agenda or that, in making the lecture, he felt he was serving a particular cause (Mbeki's cause). Perhaps he does and he was. That is, however, irrelevant. For the merits of his argument can only be properly gauged by measuring and testing the strength of the evidence he presents.

A failure to do this can only mean one of two things: either the opposing side is unable to contest the evidence (in other words, it is irrefutable) or they have chosen to appeal to people's emotions rather than any rational consideration. If the former is the explanation, the various responses above are a sign of desperation, if the latter, the responses are best described as insulting to the South African public. Most likely though, they are a bit of both.

Gareth van Onselen is the DA's director of special issues. The views expressed in the article are the author's and are not necessarily shared by the Democratic Alliance. Originally published on http://www.insidepolitics.org.za/