Protestant ethic is Max Weber’s term for the disciplined work ethic, this worldly concerns, and rational orientation to life emphasized by Jon Calvin and his followers.
Definition Two:
Protestant ethic is the belief of certain Protestants, especially Calvinists, that hard work is a Christian duty that builds moral character. Weber theorized that these Protestant values of hard work and thrift as well as beliefs in predestination caused Calvinists (and to a lesser extent other Protestant sects) to search for clues as to whether one was saved. Over time they came to see worldly success as evidence that they were among the elect. This led them to value profit and facilitated the transition to capitalism.