"A professor must have a theory as a dog must have fleas"

This quote by H. L. Mencken is a funny method of saying that a professor must have a theory in order to succeed. It indicates that having a theory is as important to a teacher as fleas are to a pet. This quote is a pointer that having a theory is a vital part of being a professor. It is a way of understanding the world and making sense of the data that is collected. Without a theory, a teacher would be not able to understand the data and would be not able to draw meaningful conclusions. This quote is a suggestion that having a theory is a vital part of being a professor and is necessary for success.