Amazon CEO Jeff Bezos defended his pursuit of space travel with his Blue Origin rocket venture, telling a crowd at Wired’s 25th anniversary summit in San Francisco that it’s only by taking big risks and pursuing personal visions that humanity can progress in meaningful ways. Bezos became the world’s richest person in July, thanks largely to increases in Amazon’s stock price. He has since faced criticism for how he decides to spend his wealth, although the executive did just announce a $2 billion nonprofit initiative to fund public preschools for low-income communities.

“I will not spend one minute of my life on anything that I don’t think is contributing to civilization and society,” Bezos told journalist Steven Levy, responding to a question on whether Bezos’ fortune, which is now nearly $150 billion according to Bloomberg, would be better spent solving practical problems like poverty instead of space travel. “You want risk-taking. You want people to have visions that most people won’t agree with. If you have a vision that everybody agrees with, you probably shouldn’t do it because someone else will do it first. All of the real needle-movers are driven by being right when most of the world is wrong.”

“You want people to have visions that most people won’t agree with.”

As Bezos has faced increased scrutiny for how he uses his resources, so too has Amazon, in particular how it treats its contract and warehouse labor forces, how much it pays its employees, and how much it gives back to communities. The company recently raised the minimum wage of all of its employees to $15 an hour after criticism from Sen. Bernie Sanders (D-VT). However, some critics now question whether the company’s breakneck expansion into offline retail, robotics, and the smart home may eventually result in widespread job loss, lowered competition in the marketplace, and more consolidation of corporate power.

Bezos clarified early in his response to the question that only governments can solve problems at scales of immense magnitude. “We want individuals to be able to pursue things they think are important and we want governments to pursue things that are important,” he said. Noting that governments are typically more conservative, he said the scale at which they operate is necessary to solve problems like nationwide education, healthcare, and poverty. “There are things only governments can do, just because of scale. My Amazon stock is tiny compared to the resources of the US federal government.” Bezos went on to defend Amazon’s work with the US Department of Defense — the company is a frontrunner for a lucrative Pentagon cloud computing contract — by saying the US is a country worth defending because it is still the greatest on Earth.

In his closing remarks, Bezos discussed his $42 million project to build a 10,000-year clock inside a hollowed out mountain in Texas, construction for which started back in February. Bezos acknowledges that right now, it may seem trivial — wasteful even — compared to the real problems of humanity. But he wants it to be a symbol for how we think about our role as a species on a scale of hundreds to thousands of years.

“We can no longer afford to think short-term. We need more symbols for long-term thinking,” Bezos said. “I believe the clock will accomplish nothing for a few hundred years. We’ll build it and people will make fun of it for a long time.” But once it’s old, he says he will likely be revered. He hopes it will stand as a symbol for the value in looking ahead and solving long-term problems.