While Elon Musk would like to take a trip to the moon and to Mars — "I think that would be quite fun," he recently told "CBS Sunday Morning" — he has more important reasons for his ambitious goals: He says SpaceX will help enable humans to become a multi-planetary species, and with electric car company Tesla, he aims to accelerate the global adoption of sustainable energy.

So what inspires and guides Musk?

At least in part, Musk says he is inspired by Douglas Adams, the author of the ultra-popular science-fiction novel, "The Hitchhiker's Guide to the Galaxy."

"My sort of philosophical foundation is in line with Douglas Adams," Musk told "CBS Sunday Morning," according to a transcript published Sunday. "Everyone has their sort of favorite philosopher, but my favorite philosopher is Douglas Adams."

Adams' iconic "Hitchhiker's Guide," first published in 1979, tells the tale of Arthur Dent. Dent is saved from the total destruction of Earth by Ford Prefect (an alien Dent at first thinks is human), who is working on a travel guide for intergalactic travelers. The science fiction novel approaches broad philosophical questions — about the meaning of life, the absurdity of life, the nature of intelligence and the nature of life — with humor.

Adams has "got great attitude, and he's a fun guy and a good sense of humor," Musk said. But more fundamentally: "What he was essentially saying is, 'The universe is the answer; what are the questions?'" Musk told "CBS Sunday Morning."

To ask the most prescient questions requires constantly expanding humanity's collective intelligence, according to Musk.

"If we expand the scope and scale of consciousness, then we are better able to understand what questions to ask. We'll learn more, we'll become more enlightened. And so we should try to do the things that expand the scope and scale of consciousness," he said.

Both SpaceX and Tesla can be, Musk believes, understood based on this theory.

"Becoming a multi-planet species and ensuring that we have a sustainable climate on Earth, these are very important to that overarching philosophy," Musk said. "So that's the philosophy I buy into."