Unlike Scottish Green leader Patrick Harvie, who said he would "sigh" if Yes lost, Kane would take defeat very badly.
"It will be a heart blow and a head blow," he says, sitting in Glasgow's CitizenM hotel.
"I would need to reconstruct a large part of myself."
He claims Scotland will not be a nice country if independence is rejected.
"It will be a depressed place for quite a while. I think there will be a leak of optimism, idealism, passion and energy. The balloon will go down considerably."
Kane is no fair-weather friend for independence, having supported the policy for 25 years.
The 50-year-old left-winger has an eclectic CV: he was one half of Coatbridge pop act Hue and Cry who now spends his time as a writer, independence campaigner and "futures consultant" for an "innovation" charity.
However, like some intellectual types, he can at times struggle to communicate in a way that appeals to the masses he wants to liberate.
In 2012, the Radical Independence Campaign (RIC) met to discuss socialism and other issues.
Here's how Kane described it: "It would seem to me that Brecht's tough self-admonition about the interpersonal anger and aggression of the radical had an answer today in the Radisson Hotel."
Can he see why some people regard him as pretentious?
"I think the tall poppy syndrome in Scotland has to be ruthlessly extirpated," he says. "Pretentious is a badge of honour for me."
Kane joined the Yes Scotland advisory board in 2012, but on condition Yes took no money from SNP-supporting tycoon Brian Souter, who had previously bankrolled a referendum to stop a government policy on gay rights.
He says of Souter: "The guy is a pernicious influence in Scottish public life."
He predicts a "narrow win or a thumping win" for Yes, but all the polls show Yes is behind and last week's debate between Alex Salmond and Alistair Darling did not help his side.
Isn't Yes running out of time? "I think there's a deep process running that is not calculable from people talking to opinion pollsters," he replies.
"There's a lot of soul-searching going on. And there's a lot of deep cogitation going on."
Kane is closer to the Green vision of independence than what he describes as the SNP's "indy-lite" manifesto.
If Scotland votes Yes, he wants the disparate Left elements - spanning the SNP, Labour, Greens, SSP and groups such as RIC - to form a new party and contest the 2016 election.
"I think there is a glorious opportunity for a coherent, social democratic platform to be built," he says.
He also thinks the SNP will be wound up after independence: "It might get through the 2016 election, but I'd be surprised if it exists beyond that."
The SNP insists the Queen will be head of state in an independent Scotland, but Kane says this should be a short-term arrangement.
He would like to strip the Royal Family "down to bicycles" before moving to a republic.
How soon could the monarchy be replaced?
"Quite soon, I would say," he says. "I think it would probably be for the second term."
Kane believes the No campaign has created a "spectacle of scepticism", but he sounds a tad conspiracy-theorist when he suggests it is a co-ordinated effort between the state and media.
"I think it's been a masterful top-down job, led by friends of the British establishment, pliant media and a state broadcaster that should somewhat hang its head in shame in terms of its approach to the spinning and shading stories to unravel the plausibility of independence."
Isn't that paranoia?
"I don't think it's paranoia at all. I think it's empirical," he says.
Kane is a fan of the wider Yes movement - the hundreds of groups that have sprung up around the country - but he does not like everybody in the campaign.
In the 1990s, Kane, his then wife Joan McAlpine and Tommy Sheridan were friends, with the latter two co-authoring a book on the poll tax. Kane dislikes Sheridan intensely.
"Tommy is as damaged goods as it gets in Scottish politics. I've no time for the man," he says.
Back on policy, Kane says reducing "inequality" is one of the top issues for him in an independent Scotland.
However, there is an elephant in the room.
If he cares so much about inequality, why were his children educated privately?
"I have an answer to this which is quite clear.
"You should ask my ex-wife about that. The clue is in the 'ex'."
He did not agree with the decision: "I never have and I never will. It wasn't entirely under my control."
He describes the matter as "private grief", but says McAlpine, now an SNP MSP, is a "great asset" to Scottish public life.
Depending on your perspective, Kane is either a valued pro-Yes intellectual, or a chatterbox who has read too many books by French post-modern theorists.
On September 19, he will find out whether the theory of independence is to become a reality.