Multiculturalism is central to our very way of life in Australia. The essence of multiculturalism is the coming together of various cultural traditions and ideas, and the consequent emergence of an eclectic melange wherein the whole exceeds the sum of the parts. Inextricably associated with this are the unassailable principles of respect, tolerance, diversity and the rights and responsibilities that come with individual freedom.
Multiculturalism has served our nation wonderfully, and is one of the key reasons Australia is feted. There are people the world over prepared to risk their lives to have a chance to approximate the lifestyle we have established, through diligence and decency and good fortune. Along with multiculturalism, other cornerstones people desire to emulate include a stable and secular polity, human rights, the rule of law and a market economy. 
The myriad statistical evidence of the extent of our multiculturalism, of our ethnic diversity, is well-rehearsed; it is not necessary to list here. A handy summary is that as many as one in four of us was born outside Australia and close to half of us have at least one parent born outside Australia.
Again, the paramount point to make is that multiculturalism is one of the key reasons this nation is, and is seen to be, a decent land, a place where equality of opportunity is an engine of the achievements of individuals and of communities. Our diversity has been the result of enlightenment and serendipity. The growth of our population and of our economy is primarily driven by immigration. But it has not all been under our control. Australia has benefited massively by accepting people seeking safety from conflict and horror. Examples include the influx of Europeans after the Second World War, and of Vietnamese fleeing war in the 1970s. It is poised to happen again as we welcome Syrians driven from their homes by terrorists.
An annual survey released this week by Monash University indicated widespread support in Australia for multiculturalism. But it did also suggest pockets of prejudice, particularly towards Muslims, and other events in the past week have underlined why we need to be vigilant in protecting and promoting the overwhelmingly positive role multiculturalism has in this country.
History will come to judge as inhuman and illegitimate the policies of our recent governments towards people seeking asylum. The embarrassed and scornful response many observers had to former prime minister Tony Abbott's championing of such polices in a speech in London this week shows the growing disdain with which such malignant meanness of spirit is viewed. Sensible people should not cease to voice their opposition to such policies until they are gone.
Likewise, decent Australians should call out the apparent vandalism against multiculturalism that was evident in Melbourne on Friday when a knife-wielding man attacked a young Muslim woman in a headscarf.
It should, too, be called out when people become unduly angry at the idea that during a religious festival, some young people feel unable to sing the national anthem. That is simply an expression of freedom, one of our core values.
And it should be called out, again and again, in the face of the most egregious blot on our nation, a shameful set of injustices that challenge the feel-good idea that we are pretty much getting multiculturalism right. As the refusal by a taxi driver in Melbourne to drive the man who had just been honoured with the title of Victorian senior of the year, Uncle Jack Charles, indicated, indigenous Australians get nowhere near a fair go in the multicultural land to which they have contributed the oldest culture. Until they do, we will remain unable to fully celebrate multiculturalism.