"First of all, this is not television."

With those words, Philadelphia Common Pleas Court Judge M. Teresa Sarmina ended her orientation for 20 jurors – 9 women and 11 men – who Monday began hearing what could be up to three months of testimony in the trial of a church official and priest involving the clergy sex-abuse scandal in the Archdiocese of Philadelphia.

Not television? That's an understatement.

It's not just a reality check for jurors. Judges don't bang gavels to open and close court sessions and most people understand that TV, movies and theater alter reality for dramatic effect.

For jurors, the trial is a crash course in logic and philosophy: learning to live according to a new reality that exists only in a courtroom and has its own language and rules of behavior.

Want to learn the philosopher's trick of holding two opposing thoughts at the same time? Jurors are told repeatedly that they "are the judge of the facts" and that only their individual, and ultimately collective, memory of testimony and evidence establishes those facts.

Yet the courtroom combatants – prosecution and defense lawyers – will argue with passion and rhetoric that the jury should accept their interpretation of the facts. And then the judge will remind the jurors again that nothing the lawyers and the judge say is evidence, that only the jurors may determine the evidence.

But not quite yet. Jurors have to keep an open mind and not judge what they've heard until after the trial ends, the closing arguments are over and the judge instructs them in the law. Which law the jury must apply as the judge instructs them to the facts that only they can decide.

As a juror, you may take notes but your notes are not necessarily better than the memory of a juror who does not take notes. And no cheating. Don't read newspaper articles about the case, listen to or watch broadcast or cable news, do any original research, visit crime scenes or use any form of social media or the Internet to discuss the case. Don't talk to your spouse, family, friends, coworkers or anyone else about the case. Don't even talk to other jurors about the case until you all begin deliberations.

Despite the fact that many citizens consider arrest evidence of guilt, jurors must accept the "presumption of innocence," that no matter what the defendant is accused of, he or she is not guilty until after the jury hears the evidence and decides guilt "beyond a reasonable doubt."

Not beyond all doubt, the judge will tell the jurors in her instructions before deliberations begin. That's impossible. It's beyond the type of doubt that would cause the average person to hesitate in a matter of personal importance: getting married, buying a house, changing jobs.

Got it?

Maybe that's why some judges remind jurors that jury service is second only to military service among civic duties. Amazingly, despite the cynicism that marks so much of popular culture, my interviews with jurors over the years show most believe it, take the job seriously and are profoundly changed by the experience.

And with good reason: they are now considering the fate of another human being. As veteran defense attorney Thomas A. Bergstrom, who is representing Msgr. William J. Lynn in the trial, reminded the jury in his opening statement: "You've been empowered by the Constitution to make sure that this system actually works."