tenure的目的是保护学术自由，使教授不至于因为外部压力而丢了饭碗。在没有学术自由的中国也搞tenure，不是很好笑么？

“Academic tenure is primarily intended to guarantee the right to academic freedom: it protects teachers and researchers when they dissent from prevailing opinion, openly disagree with authorities of any sort, or spend time on unfashionable topics. Thus academic tenure is similar to the lifetime tenure that protects some judges from external pressure. Without job security, the scholarly community as a whole might favor "safe" lines of inquiry. The intent of tenure is to allow original ideas to be more likely to arise, by giving scholars the intellectual autonomy to investigate the problems and solutions about which they are most passionate, and to report their honest conclusions. In economies where higher education is provided by the private sector, tenure also has the effect of helping to ensure the integrity of the grading system. Absent tenure, professors could be pressured by administrators to issue higher grades for attracting and keeping a greater number of students.”