We all need to be alert to the dangers of bullshit.

In 1998, the medical journal The Lancet published a study co-written by British physician Andrew Wakefield. It claimed that there may be a link between the widely used MMR vaccine and autism.

But there wasn’t. Multiple later studies found no link at all, and it turned out that Wakefield’s study was deeply flawed. The Lancet even retracted the paper in 2010. It now counts as one of the most comprehensively discredited studies of all time. It was bullshit.

And yet its influence has been huge. The “antivax” movement is still going strong, vaccine rates in the US are lower than they were before, and cases of measles are up.

The sad truth is that it’s far, far easier to make people believe bullshit than it is to make them change their minds.

But we all have a duty to try.

The key message here is: We all need to be alert to the dangers of bullshit.

Bullshit isn’t just a modern phenomenon. Back in ancient Greece, Plato accused the Sophists, a rival school of philosophy, of dealing in bullshit. He said they were only interested in winning arguments, not in what was actually true.

The twenty-first century, however, provides bullshit with an especially fertile breeding ground. These days, bullshit often claims to be rigorously grounded in science, like Wakefield’s vaccination study. Or it uses seemingly irrefutable evidence like photographs.

You might remember a story that came out after the Boston Marathon bombing in 2013. The story claimed that an eight-year-old girl from Sandy Hook Elementary School had been killed – there was even a photo of her running. The story was shared by more than 92,000 people on social media.

You guessed it: it was false. The girl in the photo hadn’t even run the race – it wasn’t open to children. But the story just proved too irresistible not to share.

That’s just one example of how modern technology like social media can spur bullshit on. If bullshit like the vaccination study can catch on as widely as it did back in 1998, imagine the harm that can be done in the age of Twitter.

Factor in our hyperpartisan news networks, factories churning out fake news, and the ease of image manipulation, and we’ve got ourselves a full-on bullshit crisis. We need to take action – now.