Is there a difference between a sensei and a consultant?

Two years ago, I advocated dropping the “Sensei” nonsense but it soldiers on. Blog readers keep asking questions about it. Consultants who do not speak Japanese keep answering that there is a fundamental difference between a sensei and a consultant, and seeing a deep meaning in the word “Sensei” that just isn’t there. There is indeed a difference, but it is basic: “Sensei” is a polite term for schoolteachers and other instructors, while a consultant is someone who gets paid for an engagement, as opposed to an employee. One word refers to a role; the other one, to a business relationship.