[100] For a description of the comparative merits of the various methods of selecting judges, see pp. 113-114. The _term_ for which all the regular federal judges are appointed is good behavior. This is virtually for life, since they cannot be removed except by impeachment.[101] All other officers of the United States are appointed for definite terms, usually for four years. Except in a few states, the state judges are elected for definite terms ranging from two years to twenty-one years (p. 113). The framers of the federal Constitution, however, were deeply impressed with the advantages of a judiciary possessing the qualities of permanency and independence, and they wisely provided that the judges should hold their offices so long as their official conduct was above reproach. [101] For a list of federal judges who have been impeached see p. 194. _Compensation._--The Constitution declares that the judges shall receive at stated times a compensation for their services which shall not be diminished during their continuance in office. As we have seen, the compensation of the President can neither be increased nor diminished during the time for which he is elected, but the prohibition in the case of the judges applies only to a reduction of their salaries. Increases are permitted to be made at any time. The compensation now allowed the chief justice of the Supreme Court is $15,000 a year, and the associate justices $14,500, amounts which are low in comparison with the salaries of the highest English judges, who receive $25,000 a year. The circuit judges receive $8,500 a year, and the district judges $7,500. Any judge of a United States court having held his commission ten years and having attained the age of seventy years, may retire from the bench and receive the same salary during the rest of his life that was payable to him at the time of his resignation. Few judges do retire, however.