Over the past few years Peter Schiff has consistently predicted that gold was headed higher, and has consistently been proved wrong. On Thursday, he vigorously defended his calls in a heated debate with trader Scott Nations, who calls his confidence "dangerous."

Back on Oct. 25, 2012, with gold at $1,700, Schiff said on CNBC's "Futures Now" that "one day we're going to look back at $1,700 with nostalgia. People are going to be shocked at how inexpensive gold was when it could be snapped up for such a bargain price. And it's not going to take too long. I mean, just in a few years, we're talking gold $5,000."

When pressed on when that might happen, Schiff said: "I think you're going to see a big move some time in the next couple of years."

Two years later, traders are indeed looking back at $1,700 with nostalgia, but only because gold is trading closer to $1,200 per troy ounce. So what does Schiff tell those who bought gold on his recommendation back then?

"Keep buying!" he exhorted Tuesday on "Futures Now." "$1,700 is still going to look cheap compared to where the market is going to go. Obviously, it's going to take a little bit longer than what I believed at that time, because so many people are still fooled that what the Fed did worked…. I think it'll go through $2,000 very quickly, and people will be upset that they didn't buy gold at $1,700."

Yet that unrepentant reply didn't sit well with Scott Nations of NationsShares, who jumped in to ask Schiff: "When are you ever wrong? And how do you ever learn if you're never wrong?"

"First of all, I've been consistantely telling people to buy gold since it was under $300, so people who have been following my advice for the past 13 years and have bought gold are actually doing better than the people who just bought stocks," Schiff retorted.

"I think it's going to $5,000," Schiff continued, denying that his claim had been proved incorrect. "I never came on the show and said, 'Hey, I guarantee in two years, gold's going to be $5,000.' You always wanted to press me…. You asked me when. I don't know when it's going to happen!"

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Schiff said his record hold up well against those of other financial prognosticators.

"How long was I coming on CNBC talking about the housing bubble and you guys were laughing at me when I was forecasting the financial crisis?" he said. "I'm the only person on CNBC who got it right! Nobody else, just me."

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"So you're never wrong," Nations deadpanned. "Peter, I think that is actually just dangerous. This is dangerous."

"I will tell you, I am wrong less often than every other guest that comes on this program, bar none," he responded. "I generally get things right…. The structure of the economy has been weakened dramatically by the Fed. The problem is, you guys don't know that. You were so fooled by the phony economy before the financial crisis, and you're just as fooled now."

"When you get blindsided by the next crisis, hopefully you'll apologize to me, because you didn't do it last time," Schiff concluded.

—By CNBC's Alex Rosenberg.

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