"Empathy for one party is always prejudice against another."

Sen. Jeff Sessions, fervid critic of Judge Sonia Sotomayor and President Barack Obama, uttered these startling words in the first hour of the Senate Judiciary Committee confirmation hearings for Sotomayor's elevation to the U.S. Supreme Court.

As professors who strive to teach students that the understanding of texts and of life is deeply enriched by ethical principles of empathy, conscience and compassion, we were left aghast by the empathy-bashing on national television.

What is empathy, and why are Sessions and other conservative Senators saying such terrible things about it?

Empathy is commonly defined as the ability to imagine, identify with, and potentially share another's experiences, perspectives and feelings. It is about process, rather than result, and about intellect as well as emotion.

Given that all of us are both shaped and limited by our lived experiences, how can we engage in effective dialogue, debate and analysis unless we try to comprehend how others think and feel?

Empathy is not a trendy or new-fangled invention of Obama, Sotomayor or even contemporary American culture.

Its rich intellectual tradition includes giants of Western political thought like John Stuart Mill, who argued in "On Liberty" that we must understand others' points of view, right or wrong, to understand, clarify, and, if need be, correct our own positions.

The 19th century British poet Percy Shelley argued that a person, "to be greatly good, must imagine intensely and comprehensively" and must "put himself [or herself] in the place of another and of many others."

Simplistic equations of empathy with bias woefully misinterpret the nature of both concepts. Genuine empathy requires crossing boundaries of identity and circumstance to find common overarching truths.

Bias stems from the refusal to acknowledge that our world-view is in part limited by our own experiences. Education is one way to eliminate such bias and limitation, and empathy is another. In literature, law and life, the exercise of empathy enlarges our capacity to appreciate and understand the narratives and perspectives of others unlike ourselves.

For judges — especially those who serve on the highest court in the land — the quality of empathy can be an antidote to prejudice, rather than evidence of it. Diversity of backgrounds and life experiences among the nine members of the Supreme Court will increase the likelihood that doctrinally and ethically rigorous exchanges will occur.

The noted legal thinker and Supreme Court justice Oliver Wendell Holmes wrote, "The life of the law has not been logic; it has been experience. "... [L]aw cannot be dealt with as if it contained only the axioms and corollaries of a book of mathematics."

Even before he nominated Judge Sotomayor, President Obama created controversy by stating that he considered "the quality of empathy, of understanding and identifying with people's hopes and struggles as an essential ingredient for arriving at just decisions and outcomes."

Yet, he was not advocating this so-called empathy standard as the sole or primary criterion for appointment of Supreme Court justices.

Clearly, serving on the highest court in the land requires an exceptional legal mind and record, but also the wisdom to know that empathy is a strength rather than a weakness.

Margaret Russell, an Oakland resident, is a professor of Constitutional Law at Santa Clara University, and board member of the Equal Justice Society and the ACLU. Marilyn Edelstein is an associate professor of English at Santa Clara University.