Zaky Mallah made a hotheaded outburst on live television during Monday night's Q&A program on ABC-TV. He has since claimed his tone of voice was perhaps too harsh, which is sophistry, for his words alone were enough to cause offence. Yet Mr Mallah has the freedom to think and say foolish things. Australian ears are not so precious that he must be silenced. Better he be heard, and his muddle-headed logic exposed.

It is not for The Age to defend the decision by the ABC to put Mr Mallah to air, which the broadcaster now regards as a mistake. Mr Mallah has a criminal conviction for threatening to kill a Commonwealth officer and was acquitted on terrorism charges, and told the audience such when posing his question to the panel. People can judge his views for themselves, in light of this record. But The Age does defend the principle of free speech, and inherent to that notion is the strength of ideas to persuade people of the rights and wrongs of any argument. Nothing exposes like exposure, and to the extent Mr Mallah reflects anyone's view beyond his own, he must be listened to in order to be effectively countered.

In that light, Prime Minister Tony Abbott was wrong to demand of the ABC "Whose side are you on?" after the broadcast, and again on Wednesday after the program was repeated. This smacks of populist point-scoring rather than a genuine concern about the security of the nation. Is Mr Abbott's faith in the power of free speech so feeble that neither he nor the members of his government can puncture Mr Mallah's opinion, so instead seek to attack the messenger?

Mr Mallah appeared to claim on Monday night that Muslims would be justified in joining Islamic State in Syria because of what a Liberal politician on the panel had said, and if that is indeed what he meant, it is plainly ridiculous. Islamic State has a record of wanton brutality and intolerance that brooks few historical comparisons, and seeks to inspire random attacks against civilians across the world. Nothing any Australian politician has done or said can justify this vicious rampage.

Age columnist Waleed Aly challenged Mr Mallah about his views during a subsequent television interview on Channel Ten's The Project and effectively demonstrated the power of argument to expose fallacy. Indeed, Mr Abbott himself was heady with praise for ABC Lateline host Emma Alberici last year after she refused to be distracted by verbal fireworks when asking a Hizb-ut Tahrir spokesman if he condemned the record of Islamic State. "I think she spoke for our country," Mr Abbott said at the time – but that would only be true because Australia is a country that supports free speech, not a type of speech where governments alone should be the judge of right and wrong.

The hysteria generated by Mr Mallah's comments and the ABC's airing of them has been remarkable. In particular, some of the coverage in News Corporation newspapers has been juvenile and demonstrates a fickle attitude towards free speech from that media organisation.

Drawing the line for any freedom is complicated, shown by the proposals to amend the racial discrimination act, which The Age supported but the government chose not to pursue. But it is clear the law is already sufficient to deal with Mr Mallah had he crossed a line to incite violence or hatred on Monday, which he did not.

Mr Abbott on Wednesday described the ABC as the "supposed national broadcaster". His use of the word "supposed" suggests a belief that the ABC has a responsibility, perhaps by dint of its taxpayer funding, to toe the government line. Australia would be the poorer if speech were less free.