VATICAN CITY, OCT. 31, 2003 ( John Paul II says that peace requires the purification of the memory of individuals and peoples through forgiveness.

It is "an indispensable premise for an international order of peace," the Pope said in a message made public today to participants in a congress organized by the Pontifical Committee for Historical Sciences. The congress commemorated the centenary of the death of Pope Leo XIII.

The Holy Father said "that those who do research on the roots of conflicts discover that the negative consequences of events in the past continue to be present."

"Frequently, these contaminated memories have become integral elements of the national identity, and in some cases, even of the religious identity," he said.

"This is why we must renounce any manipulation of the truth," he added. "The historian's love for his own people, community, even religious community, must not compete with the rigor for scientifically prepared truth. It is from here that the process of purifying the memory begins."

"This effort to purify one's memory entails for individuals as well as peoples the recognition of errors for which they must ask forgiveness," the Holy Father continued.

"This sometimes requires much courage and self-denial. However, it is the only way that social and national groups, freed from the remnants of old resentment, can come together with fraternal and reciprocal loyalty in order to build a better future for all," John Paul II explained.

In his message, the Holy Father said that like "Leo XIII, I too am personally convinced that bringing to light the full truth about the 2,000 years of Church history, through science, benefits her."

Historians must not "be accusers or judges of the past, but must attempt to patiently understand each event with the maximum depth and amplitude, in order to delineate a historic context as close as possible to the truth of the facts," he concluded.