Eight years ago, I was haunted by an evil spirit. I was 25 at the time, and I was living in a tiny house behind someone else's house in Los Angeles. It was this guest house, it had kind of been dilapidated, not taken care of for a long time. And one night, I was sitting there and I got this really spooky feeling, kind of the feeling like you're being watched. But no one was there except my two dogs, and they were just chewing their feet. And I looked around. No one was there. And I thought, OK, it's just my imagination. But the feeling just kept getting worse, and I started to feel this pressure in my chest, sort of like the feeling when you get bad news. But it started to sink lower and lower and almost hurt. And over the course of that week, this feeling got worse and worse, and I started to become convinced that something was there in my little guest house, haunting me. And I started to hear these sounds, this "whoosh," kind of whisper, like something passing through me. I called my best friend, Claire, and said, "I know this is going to sound crazy, but, um ... I think there's a ghost in my house, and I need to get rid of it." And she said -- she's very open-minded -- and she said, "I don't think you're crazy. I think you just need to do a cleansing ritual." (Laughter) "So get some sage and burn it, and tell it to go away." So I said, "OK," and I went and I bought sage. I had never done this before, so I set the sage on fire, waved it about, and said, "Go away! This is my house! I live here. You don't live here!" But the feeling stayed. Nothing got better. And then I started to think, OK, well now this thing is probably just laughing at me, because it hasn't left, and I probably just look like this impotent, powerless thing that couldn't get it to go away. So every day I'd come home and you guys, this feeling got so bad that -- I mean, I'm laughing at it now -- but I would sit there in bed and cry every night. And the feeling on my chest got worse and worse. It was physically painful. And I even went to a psychiatrist and tried to get her to prescribe me medicine, and she wouldn't just because I don't have schizophrenia, OK. (Laughter) So finally I got on the internet, and I Googled "hauntings." And I came upon this forum of ghost hunters. But these were a special kind of ghost hunters -- they were skeptics. They believed that every case of ghosts that they had investigated so far had been explained away by science. And I was like, "OK, smart guys, this is what's happening to me, and if you have an explanation for me, I would love to hear it." And one of them said, "OK. Um, have you heard of carbon monoxide poisoning?" And I said, "Yeah. Like, gas poisoning?" Carbon monoxide poisoning is when you have a gas leak leaking into your home. I looked it up, and the symptoms of carbon monoxide poisoning include a pressure on your chest, auditory hallucinations -- whoosh -- and an unexplained feeling of dread. So that night, I called the gas company. I said, "I have an emergency. I need you to come out. I don't want to get into the story now, but I need you to come out." (Laughter) They came out. I said, "I suspect a gas leak." They brought their carbon monoxide detector, and the man said, "It's a really good thing that you called us tonight, because you could have been dead very soon." Thirty-seven percent of Americans believe in haunted houses, and I wonder how many of them have been in one and how many of them have been in danger. So that haunting story has led me to my job. I'm an investigator, and I'm an investigator in two senses: I'm an investigative journalist, and I'm also an investigator of the claims of the paranormal and claims of the spiritual. And that means a few things. Sometimes that means that I'm pretending to need an exorcism so I can get -- yes, that's right! -- so I can go to an exorcist and see if he's using gimmicks or psychological tricks to try to convince someone that they're possessed. Sometimes that means I'm going undercover in a fringe group which I report on for a podcast that I co-host. And I've done over 70 investigations like this with my co-host, Ross. I would love to tell you that nine times out of 10, science wins, saves the day, it's all explained. That's not true. The truth is, 10 times out of 10, science wins, it saves the day. (Applause) And that doesn't mean there's no such thing as a mystery. Of course there are mysteries, but a mystery is a mystery. It is not a ghost. Now, I believe there are two kinds of truth, and it's taken me a while to get to this place, but I think this is right, so hear me out. I think there is outer truth and there's inner truth. So if you say to me, "There was a man named Jesus and he once existed," that's outer truth, right? And we can go and look at the historical record. We can determine whether that seems to be true. And I would argue, it does seem to be true. If you say, "Jesus rose from the dead," -- ooh, trickier. (Laughter) I would say that's an outer-truth claim, because he physically rose or he didn't. I'm not going to get into whether he rose or he didn't, but I would say that's an outer-truth claim. It happened or it didn't happen. But if you say, "I don't care whether he rose from the dead. It's symbolically important to me, and that metaphor is so meaningful, so purposeful to me, and I'm not going to try to persuade you of it," now you've moved it from outer truth to inner truth, from science to art. And I think we have a tendency to not be clear about this, to try to move our inner truths to outer truths, or to not be fair about it to each other, and when people are telling us their inner truths, to try to make them defend them by outer-truth standards. So I'm talking here about outer truth, about objective things. And there was an objective reality in my haunted house, right? Now that I've told you about the gas leak, I doubt a single person here would be like, "I still think there was a ghost, too" -- (Laughter) because as soon as we have these scientific explanations, we know to give up the ghost. We use these things as stopgaps for things that we can't explain. We don't believe them because of evidence; we believe them because of a lack of evidence. So there is a group in Los Angeles called the Independent Investigations Group, or the IIG, and they do great work. They'll give a $10,000 prize to anyone who can show, under scientific conditions, that they have a paranormal ability. No one's done it yet, but they've had a couple people who claim that they were clairaudients, which means that they can hear voices either from the great beyond or they can read minds. And they had one person who was very sincere, who believed that he could read minds. So they set up a test with him, and this is the way it always works. The group says, "OK, we have a protocol, we have a way to scientifically test this. Do you agree with it?" The person says yes. Then they test it. It's very important that both sides agree. They did that, they tested him. They said, "OK, you know what? You weren't able to predict what Lisa was thinking. It matched up about the same as chance. Looks like you don't have the power." And that gave them the opportunity to compassionately sit down with him and have a very difficult discussion, which basically amounted to, "Hey, we know you're sincere, and what that means is, you do hear something in your head." And that guy got to make the very difficult decision, but really the life-changing decision about whether to go get help. We're actually helping people to make these connections that maybe before seemed like otherworldly explanations, help draw us into reality and maybe change our lives for the better. Now, on the other hand, maybe one time it'll turn out to be true. Maybe we'll find out there are ghosts, and holy shit, it will be the best thing! And every time I do one of these investigations, I still get so excited, and I'm like 75 into them, and still I swear on number 76, I'm going to be like, "This is the one!" (Laughter) Maybe I'm just eternally optimistic, but I hope I never lose this hope, and I invite you to take this same attitude when people share their outer beliefs with you. When talking about testable claims, respect them enough to ask these good questions. Challenge and see how you can examine them together, because there's this idea that you can't respect a belief and still challenge it, but that's not true. When we jiggle the lock, when we test the claim, we're saying, OK, I respect you, I'm listening to what you're saying, I'm going to test it out with you. We've all had that experience where you're telling someone something, and they're like, "Oh, that's really interesting, yeah," you know you're being had. But when someone says, "Really? Huh. Sounds a little sketchy to me, but I'm listening," you at least know you're being engaged and respected. And that's the kind of attitude we should have with these claims. That's showing someone that you care what they're saying. That's respect. Now, yes, most of these searches will come up empty, but that's how all of science works. Every cure for cancer so far has not panned out, but we don't stop looking, for two reasons. Because number one, the answer matters. Whether it's looking at the afterlife or the paranormal or the cure for cancer, it all amounts to the same question: How long will we be here? And two, because looking for the truth, being open-minded, and being willing to be wrong and to change your whole worldview is awe-inspiring. I still get excited at ghost stories every single time. I still consider that every group I join might be right, and I hope I never lose that hope. Let's all never lose that hope, because searching for what's out there helps us understand what's in here. And also, please have a carbon monoxide detector in your home. Thank you. (Applause)