However, I want to argue that a new type of teacher is evident, whose emergence has been influenced by alternative interpretations of what loyalty entails. A "professional" perspective might conclude that what matters are the standards and values set out by the General Teaching Council for Scotland and teachers' organisations such as the Educational Institute of Scotland. These could be read as suggesting that collective loyalty to one's fellow professionals is more important than to individual learners.
Then there is the "managerial" perspective. This starts from the view that teachers, like other employees, should be loyal to the organisation which appoints them and pays their salaries. Thus, they should not express public criticism of policies pursued by local authorities with which they disagree.
Contracts of employment sometimes make it clear that there are limits to freedom of speech. The notion that teachers might owe a higher loyalty to knowledge and truth does not get much sympathy within the bureaucratic world of local government.
The gradual ascendancy of professional and managerial views on loyalty has had a noticeable effect on the attitudes of some teachers. They take an organisational line on most issues and are careful not to do or say anything that might be construed as anti-establishment. Faced with a dilemma which involves choosing between ethical and organisational values, they will invariably opt for the latter. Their loyalty to the leadership is often rewarded through the promotion system - though it may also prompt cynical comments from colleagues.
The rise of the corporate teacher has, of course, been strongly influenced by the importation of private-sector assumptions into public services such as education. It is reinforced by the discourse of collegiality, which is in the ascendancy.
These trends are not confined to the school sector. In more than 30 years working in higher education, in four different Scottish universities, I have noticed a marked decline in the quality of debate at university senates, which are supposed to be the principal arenas for discussion of academic matters.
Whereas in the past, senate meetings involved lively and sometimes robust arguments about important matters of principle, nowadays they generally take the form of rubber-stamping decisions previously determined by senior management. It is no accident that this change has coincided with the emergence of a new breed of senior academics - people who have been appointed more for their "political" and bureaucratic skills than for their intellectual leadership.
Walter Humes is research professor in education at the University of the West of Scotland.