John Safran anticipated a tangle. What else would you expect when you wade into the worlds of Australian nationalists, Islamic State supporters and the hard left?

"There's definitely an aspect where I'm happy with things not having neat answers," Safran said.

"That's another weird thing where I'm totally cool with things not being tied up because how can you tie everything up."

Safran - he of the all-but-nudie run through Jerusalem, real-life crucifixion and former Triple J radio show with Father Bob - has explored the world of the far left and far right in Depends What You Mean By Extremist. He does shots with nationalists, tries his hand at Krav Maga and watches terror suspect Musa Cerantonio make a prank call from his mum's lounge room. Somewhere around the middle of the book, witnessing violence against Rabbis and becoming immersed in anti-Semitic scripture, he starts carrying a knife. It was written "in a frantic state".

"I think that kind of comes across because I really was getting neurotic and negative about everyone and everything," Safran said.

"Then Penguin prints the book and there's a two month wait before the release and you kind of get time to decompress and start hanging out with your old friends instead of all your new crazy friends, and you kind of go I shouldn't have been so neurotic and maybe there are positive things but it's too late - the book has been printed.

"It kind of reflects my mad state at the time at least so that's kind of good but in another way I kind of think what would have happened if I'd had two months breathing room and just hung out with my dad and my hang out with my old school friends rather than the Klansmen or the old ISIS supporters. Maybe that would have been a more positive end to the book."

Some things have become clearer to Safran during his book tour, set to hit Canberra on Wednesday. What has become vastly more apparent is that Australia should've started taking religion, mysticism, scripture and belief seriously a long time ago. Instead, he said, it's twisted into something palatable for atheist audiences who aren't quite sure what to do with it all. An anti-racism rally is a front for the anarchists. White supremacists make their concerns about Islamic women rather than a platform for eugenics.

As well: "The example I give in the book is of if there's someone from the Australian Christian Lobby on Q&A he kind of talks about things like 'gay marriage goes against Australian values', and it's like ... I mean Australian values are probably to be pro-gay marriage if you go by statistics, so he's sort of not saying what he really means because it's too unpalatable and an audience won't go along with it if he says 'There's a God, and he has said that these things are right and these things are wrong, and this is wrong', no one's going to go with it so he has to bend it," Safran said.

"When Ayaan Hirsi Ali, who's that former Muslim who's a critic of Islam, when she tours, there was a video done by Muslim Australians trying to argue against her.

"Not at any one moment is there an aspect of she's blasphemous or this wounds us because we believe deeply in the Koran and there's things in Muslim scripture about apostates. None of that comes up and it's totally bent into a palatable way of where even though Ayaan Hirsi Ali is black she's actually a tool for white supremacy or white culture and it's bent into this way that is more palatable for the mainstream."

The end result? No one is saying what they really mean. And no one really knows what's going on.

"We screwed up, unfortunately," Safran said.

"Three of the leadership people who really brought [far-right party] Reclaim together were evangelical Christians who believed we're at a spiritual war with Islam, so that really drove them to do what they did and got bodies out on the street and stuff like that.

"And obviously with the Australian ISIS supporters, similarly they're really driven by faith. It feels like this is a conversation Australia has to start having 10 years ago or 15 years ago and it's like we've left it too late and now there's no way to start the discussion because everything's so heated and tangled and it's too late."

Safran doesn't feel nervous sharing what are, in some quarters, controversial views. When taken to task for taking an interest in nationalism as a white man, Safran expresses disbelief that a Jew is considered someone who doesn't have a stake in its rise. But the response to Depends What You Mean By Extremist has been, by and large, positive.

"Even if I'm wrong about things I don't think I'm wrong about things, so all these tangles I look into, if I say it's a tangle about how me as a Jewish person and a small-L liberal and I'm happy to fight Islamophobia, but there's a real strand of anti-Semitism that goes on in the Muslim world and also among the West. I just think that's true," he said.

The John Safran ANU/The Canberra Times Meet the Author event on June 7 is sold out. For the full list of upcoming authors check here: http://www.anu.edu.au/events/anuthe-canberra-times-meet-the-author-series

Depends What You Mean By Extremist is published through Penguin for $34.99.