Periodical appointments, however regulated, or by whomsoever made, would, in some way or other, be fatal to their necessary independence. —Alexander Hamilton,
Federalist No. 78

Why does Hamilton think judges should be appointed permanently rather than on a periodic basis?

Permanent appointments allow for greater regulation but less independence.
Periodic appointments promote a fatal independence.
Periodic appointments are hard to regulate.
Periodic appointments would destroy a judge’s independence.