Each year, in my last lecture to the graduating class of the Stanford Graduate School of Business, I speak of the playground rules that we’re taught as children by our parents. One of those rules is not to lie. But because lying can be so convenient, I warn them that bright people often convince themselves that as long as what they say is literally true, it’s not really a lie.

To make this point, I take them to the 2013 collapse of a garment factory in Bangladesh, which killed 1,127 workers. Cato Fashions had taken delivery of nine tons of goods from the factory already that year, but nonetheless gave the following statement to the press: “We did not have any ongoing production, at the time of the incident.” I then ask the graduating MBA students to imagine the excitement among the Cato executives when they discovered that at the moment of the collapse, none of the 3,100 workers were sewing one of Cato’s slacks. Cato’s words were indeed accurate, but nonetheless intended to mislead.

We tell ourselves that if what was said, taken literally, is correct, then it’s not really a lie. It’s a problem for smart people, because the cleverer we become, the better able we are to arrange the letters and commas in such a way that the precise sentence may be true, but the message is wholly deceptive.

What he Tweeted was technically correct—they did not use 0-Chlorobenzylidene malononitrile, or what is commonly referred to as “tear gas.” Instead they fired projectiles into the crowd containing oleoresin capsicum, which like tear gas is designed to create “uncontrollable watering of the eyes” and “nasal and sinus discharge.”

Later that Sunday, Attorney General William Barr doubled down by stating that what was used “were not chemical irritants.” With perhaps the same glee that the Cato executives felt in 2013, Barr discovered that what exploded at the feet of protestors to create “uncontrollable watering of the eyes” and “nasal discharge” was oleoresin capsicum, which is not a man-made chemical. Then, using a convenient timeline, he suggested that the clearing of Lafayette Square, and the President’s walk to St. John’s Church, was a coincidence.

Trump the businessman wouldn’t have any tolerance for a contractor trying to deceive him about the cost of building a new skyscraper, even if the words the contractor said were literally true. Neither would Barr if one of his teenage children tried to mislead him about ditching school. All of which means that, as their mothers might say, “they know better.”

I tell my students that the other person’s inability to prove a lie does not render the statement truthful; that when we use our intellect to trick or misinform, we’ve used our gift irresponsibly. I suggest that misleading is nothing more than a sophisticated way to lie.

No doubt the Attorney General has convinced himself that through his linguistic gymnastics he didn’t lie to the American public about the use of force in Lafayette Square. But William Barr’s mother knows better, and so do we.