Supreme Court Chief Justice John Roberts began Monday's Supreme Court session -- the first since the death of Justice Antonin Scalia on Feb. 13 -- remembering the longtime jurist as a colleague of "irrepressible spirit."
Roberts said Monday that Scalia was "our man for all seasons and we will miss him beyond measure."
The high court is resuming work just two days after the justices and thousands of dignitaries, friends and family mourned his loss at a funeral Mass in Washington. He was buried on Saturday.
President Barack Obama has vowed to nominate a candidate to take Scalia's seat, but Senate Republicans, backed by their party's presidential contenders, have pledged to block anyone Obama puts forward. Republicans have said the choice should await the next president.
Justice Clarence Thomas said last week that "it is hard to imagine the court" without Scalia, who served as a justice for nearly 30 years.
Scalia's sharp questioning of lawyers transformed arguments into lively sessions in which the justices sometimes seemed to be talking to each other, rather than to the lawyers arguing before them.
The void created by Scalia's death was visible on Monday. His chair, draped in black wool crepe, will remain in its usual place to the right of Chief Justice John Roberts until next month.
Only in late March do the justices plan to switch seats in line with their seniority on the court. Justice Anthony Kennedy is now the longest-serving member of the court, with 28 years of experience.
Arguments in two cases are scheduled for Monday. One involves a dispute over preferences given to military veterans seeking Veterans Administration contracts. The other case concerns whether evidence of a crime should be thrown out of court because the police did something wrong or illegal that led to the discovery of the evidence.
One of the term's biggest cases, a challenge to Texas' strict regulation of abortion clinics, awaits the court next week.