To write an abstract essay about bridges could be a challenge, but it can be done. Aldous Huxley defines an abstract essay as a combination of personal or autobiographical essay that can "look at the world through the keyhole of anecdote and description" and of objective or practical essay that directs "attention outward to some literary or scientific or political theme."
A bridge could be a physical construction built of steel or concrete to enable one to cross over a river, train tracks, or other obstacle. A bridge could also be a means of connecting with another person through a common interest or shared goal. The physical bridge could become a symbol for the mental or emotional link between two different aspects of life.
Can you identify a physical bridge that has significance in your life for some reason, and use it to examine an intellectual bridge?