The population of the United States, and particularly New York, continues to evidence growth in cultural, ethnic and racial diversity that rivals the immigration waves this country experienced in the late 19th and early 20th centuries. With this new growth comes new challenges to society and, in particular, to our legal system.

Our founding fathers, 35 of whom were lawyers, could not have imagined that this country would grow into the great diverse, multi-cultural nation that we have become. The practice of law has had to keep up with these changes. We still have to stand up for the rule of law and be truthful in our interpretation of it, however unappealing that may be.

A colleague of mine who has been practicing law for many years but started out as a young reporter related an interesting story to me about an interview he conducted years ago with a 105-year-old former slave.

My colleague asked him what advice he would offer those who wished for a long life. The response was very much to the point: “I don’t give advice. If you give people advice they want to hear it won’t help them. If you give them the advice they need, they’d hate you for it.”

This story translates well to the challenge we lawyers face every day. We must give the best advice we can, even if our clients don’t want to hear it.

So often we are painted as the ultimate pessimists, or the ultimate obstructionists. We are seen as lawyers seeking to frustrate a deal or as the voice that tells a civic board what it cannot do.

Defending unpopular causes or unpopular people never makes us popular. However, that is our responsibility as lawyers.

There is a flip side to this. Often we are the engineers of social change, presenting cases that force our judiciary or legislatures to create rules, regulations or law that keep pace with the dynamic changes of a diverse society. More times than not this is done after frank and open debate where lawyers can argue eloquently about the pros and cons on subjects as polarizing as gay marriage, immigration or educational opportunity.

A diverse society demands our continued energy as lawyers to promote a system of justice that gives everyone the opportunity to thrive in a society that, though different than the America of a century ago, still needs our protection and support.

Peter P. Zeltner is a partner with Bertine, Hufnagel, Headley, Zeltner, Drummond & Dohn in Scarsdale.