Why do we say that someone who is sincere and trustworthy is on the level?

Many words we use to describe character are related to our sense of direction and position. He’s a “straight-nosed, upright, stand-up kind of guy,” for example. Or, “she won’t mislead you; she’s a straight talker and knows which end is up.” Clearly in this right-angle universe, curves lead you astray and it’s not good to get bent out of shape.

Maybe that’s why they talk about people having a moral compass. On the level derives from another instrument used to determine direction and position. It comes from the Masons, the secretive fraternal order. They hold that the level, the tool that masons (the building crafts people) use to make sure their work is level, represents integrity.

So if you’re on the level, we can trust you because your bricks are stacked straight. That’s my slant on the matter.

Source: Morris Dictionary of Word and Phrase Origins by William Morris