Despite sharing a number of Andrews' basic precepts, one major branch of the literature differed strongly from him with regard to how strategy forms. Andrews prescribed that strategy should be deliberately and consciously decided and adopted by management. Henry Mintzberg, however, teaches that in reality strategy often emerges from actions and behaviours at various organizational levels, and furthermore that this is desirable. Thus if both views are recognized there are two major types of process through which strategy may be formed: deliberate, and emergent. There has been vigorous debate concerning the extent to which each of these strategy formation processes is usual or appropriate.