It used to be that both gravity and levity were thought to be physical forces.

Gravity was the force that made stuff go down; levity made stuff go up.

As it has worked out, gravity is a hugely important part of physics studied by giants of understanding and systemitizing, Isaac Newton and Albert Einstein. Levity is left to us daily muddlers. Not a huge physical force but a human option. If I trip because of imperfections and fall down because of gravity, I can take that event with levity, or not.