Justices, like Congressman and Senators, become products of their staffs in direct proportion to how much staff they have. The staffs put out their laws, their letters, their decisions, their press releases, their speeches. In the end, the Justice, Member of Congress, whatever, need only be sufficiently sober to cast a vote. All else can be done by others.
Congressman Billybob
If I recall correctly, Justice Douglas and Justice Brennan wrote their own opinions. Douglas did not even have law clerks on his staff, relying instead upon the pooled clerks to the limited extent that he used a clerk for menial tasks.
Did somebody say it's cocktail hour?