Recently I was asked to speak to a group of idealistic young people just starting their careers in public-interest professions. After my spiel concluded, the first question I was asked caught me completely off guard: "What is justice?"

Somehow, I have managed to work in the field of criminal justice for 25 years without developing a satisfactory response to this question. In the days since, as I have rehearsed what I should have said, I have come to realize that, for me, there are two kinds of justice: micro justice and macro justice.

Micro justice focuses on individual people and asks, "What is an appropriate response to the circumstances presented by this specific case?" Macro justice looks at the bigger picture, examining social impacts, both positive and negative, and tries to determine whether they have been distributed in a way that conforms to basic tenets of fair play.

One of the challenges that confronts the field of criminal justice is that micro justice and macro justice are not always in sync. Every day, police officers, prosecutors and judges are making decisions in individual cases that are rational, that follow all of the proper procedures, and that many would argue are correct on the merits. Unfortunately, the cumulative effect of these decisions is to achieve outcomes that, viewed in the aggregate, do not seem just.

Leadership consultants often exhort their clients to "get off the dance floor and get on the balcony." From the perspective of the balcony, it is possible to offer a fundamental critique of the justice system as an instrument for maintaining an unfair social order. The negative impacts of the justice system on black Americans stand out in particularly stark relief.

Yet the view can look very different from the dance floor. While egregious examples of brutality, incompetence and corruption do exist, the truth is that much of the daily practice of the justice system consists of well-intentioned front-line staffers attempting to do their best with challenging situations and complicated people.

This lesson was hammered home to me when I visited Rikers Island a few years ago during the height of the media coverage of violence in the New York City jail complex. Much of the reporting focused on the brutal behavior of correctional officers. I didn't meet every correctional officer on the island, of course, but those I interacted with (the vast majority of whom were women of color) never expressed contempt or hatred for those in their charge. Quite the contrary -- most conveyed genuine concern and a desire to create a safe environment.

In a similar vein, when I talk to criminal-court judges, many of them express real regret when their actions land someone in jail. When they describe their thought process, they invariably point to the length of a defendant's rap sheet, the suffering of victims and the negative effects of continued wrongdoing in the community.

So where does this leave us? How do we reconcile the reality that at the ground level many of the people in the justice system are trying to do the right thing with an overarching analysis that the system is not achieving just results?

Many of the potential answers being advanced at the moment -- for example, eliminating cash bail or closing private prisons -- are macro justice solutions that tend to limit the discretion of system actors. We need big ideas like these if we are going to improve justice in this country.

But big ideas alone are not enough. We need micro justice solutions too. Small changes in daily practice can also have far-reaching implications. We need to give front-line justice professionals the training they require to understand the traumatic life circumstances that bring people into the justice system, whether as defendants or victims. And we need to give them the encouragement and flexibility necessary to treat every person they encounter with decency, respect and individualized attention.

Perhaps most important of all, we need to convince bright young people, like the ones who initially befuddled me, to become front-line criminal-justice practitioners. The fight to transform the American justice system cannot be won from the offices of our foundations, elected officials or editorial boards. To create a fair, effective and humane justice system, we need judges, probation officials and correctional officers who are willing to wrestle with the question "what is justice?" on the ground each and every day.