Judith Sloane (“Leaning Left by association”, The Australian, 17/9) may have intended to be rhetorical by asking “When did associations representing qualified professionals become public advocates of progressive causes?”. But the answer is rather obvious: when those objectives are in the interests of their members, or accord with their values. Sloane may find it amusing, for example, that doctors organise for peace; but doctors who have treated battlefield casualties may not see the joke.

Despite the efforts of the anti-union brigade, freedom of association is still at the base of our democracy. Sloane is therefore not prevented from forming her own rival professional associations which, say, oppose social progress, or support market libertarianism, or whatever she chooses – if she can find anyone to join.