Is it a role or a job

Riding home on the bus last week with the soccer team after a game I was reading Marshall McCluhan's The Gutenberg Galaxy. He was going on about King Lear and how humanity moved from the medival world to the world of the Renaissance.

King Lear is a kind of elaborate case history of people translating themselves out of a world of roles into a the new world of jobs. This is a process of stripping and denudation which does not occur instantly except in artistic vision. But Shakespeare saw that it had happened in his time. He was not talkin about the future. However the older world of roles had lingered on as a ghost just as after a century of electricity the West still feels the presence of the older values of literacy and privacy and separateness." The Gutenberg Galaxy p.22

Is teaching your role or your job? Is it something that you do from 8 to 4 or is teaching something that defines who you are. Is teaching truly a vocation? Laptops are going to change the race to the parking lot that so many teachers who have a job have to win, and so many people who enter into the role of teacher don't even run in. What do you think about all of this?