Reid Hoffman’s fingerprints are all over Silicon Valley.

A Bay Area native, Mr. Hoffman was drawn to technology at an early age. After studying symbolic systems and philosophy in college and graduate school, he took a job at Apple in 1994.

He went on to start one of the earliest social networks, SocialNet.com, in 1997, then joined PayPal as chief operating officer in 2000. Months after selling the company to eBay in 2002, he co-founded LinkedIn and became its chief executive.

Along the way, Mr. Hoffman became one of the technology industry’s most prolific networkers. He arranged the first meeting between Mark Zuckerberg and Peter Thiel, an important early investor in Facebook, and is constantly making connections between entrepreneurs, engineers and investors.

In 2009, he stepped away from executive responsibilities at LinkedIn and joined Greylock Partners, a venture capital firm. As an investor, he has backed many of the biggest names in tech, including Facebook and Airbnb. More recently, he started a podcast, “Masters of Scale,” on which he interviews entrepreneurs about their experiences.

Mr. Hoffman has become more political of late. He is an outspoken critic of President Trump, and last year apologized after it was revealed that a group he had funded used Russian-style social media deception in a 2017 Senate race.

This interview, which was condensed and edited for clarity, was conducted at LinkedIn’s offices in New York.

What was your childhood like?

There were two obsessions I had as a child that were pretty instrumental to the path I ultimately ended up taking. One was board games and fantasy role-playing games. It was a focus on strategy, and how tactics and strategy go together. Most people know Dungeons and Dragons. Not lions and tigers and bears, but dwarves, elves and dragons, oh my.

The second is that I was an obsessive science fiction reader. I would go to the public library and would just pull the next book off the science fiction shelf and read it. Part of science fiction is imagining the world as it could possibly be, thinking about it on a scale of the change of humanity, or the change of what it is to be human, and thinking about the impact of technology on those things.

You grew up in Berkeley, Calif. Did any of the counterculture influence you?

I was running from tear gas even before I could walk, because I was on my dad’s shoulders as he was running from tear gas at a protest against the Vietnam War. A willingness to think for yourself was probably one of the things that growing up in Berkeley really helped with.

How did you get interested in technology?

At Stanford, my undergraduate major was called symbolic systems, which was artificial intelligence and cognitive science. The computer science majors would mockingly call it “C.S. light,” because you didn’t have to do the full C.S. major; you only had to do some of the introductory things. The pivot to working in tech was simply that the pay was better. I went, “O.K., if I go and do the tech internship, I’ll get paid more. I’ll go do that.” So I did a summer internship at Xerox PARC, where my job was building a simulator for a multiagent learning system. Then I did a summer internship at IBM on expert systems.

Why did you then go on to get a master’s in philosophy?

I was intensely interested in the questions of who are we as individuals in society, and who should we be. How do we think? How do we reason? How do we communicate? Philosophy doesn’t have a better understanding than anyone else. It’s still all unknown. But the thing that I learned from philosophy was an ability to articulate theories crisply, which led to an ability to express crisp theories of human nature, which aligns with some of the most interesting things around, like consumer internet and entrepreneurship. Philosophy enabled all that in a much more robust way than an M.B.A.

You can learn the technical skills, what a coding mind-set is, what data structures look like. But understanding — here is the way the world could be, here is the theory of human nature that you’re playing into in order to create that world, and here is that kind of combination of psychology, sociology and economics together with what’s possible in technology — that combination was enabled much more by philosophical thinking.

When did you start thinking about there being a social layer to the internet?

A lot of founders have some North Stars about what is going to be super important to how products evolve, how society evolves, what people can do with technology. For me, that is the notion that software is the medium by which we connect with each other, communicate, coordinate, see each other, understand each other. That instinct and intuition goes all the way back to when I first started seeing online services like CompuServe and AOL. It was just a matter of what were the configurations and patterns for doing that.