Thorstein Veblen was an American economist and sociologist in the late nineteenth and early twentieth centuries who was panning capitalism at a time when Marxism was all the rage, ultimately writing his magnum opus, The Theory of the Leisure Class, which explained many of his ideas, in 1899. It is in this book that he is best known for exploring his "habits of the mind" theory.
A prevailing philosophy of the time held that human thought was guided by certain universal principles. However, carrying this further, Veblen believed that people make sense of the world around them through naturally ingrained ways of feeling and thinking based on biological, historical, and technological stimuli.
And, like all good Marxists, Veblen connected his theory to labor activity. In his view, a habitual mindset was characterized by individuals engaging in mechanical labor routines—what he called a "machine process." Not the repetitive nature of the exercise itself, but the persistence of continual external conditions during the exercise of the labor process, created habits of mind.
In addition, the more machine-like the labor activity, the more ingrained such mental habits became. According to Veblen, "In proportion as a given line of employment has more of the character of a machine process and less of the character of handicraft, the matter-of-fact training which it gives is more pronounced."
His theory had three main characteristics. First, it said, these habits occur without sensible judgment or consideration. Second, they are highly inflexible, refusing to change even after the external factors that created them are long gone. And third, they create a basis of understanding among all people who share those similar habits of mind.