While the most crippling blow to the Pennsylvania Supreme Court may have been the indictment of Justice Joan Orie Melvin on political corruption charges — leaving the court at less than full strength and exposing it to the potential for even divisions — the most far-reaching event of 2012 was much more incremental.

That event was the emergence of Justice Thomas G. Saylor, currently the senior associate justice, as an intellectual leader of the Supreme Court.