I have invented four rough categories of truth. First, microscopic truth, whether in natural or social science, involves narrowing the field to a particular frame and excluding all variables except those to be measured. In a court of law, we pose and answer a particular question in a defined field. You identify, circumscribe and verify.
Second, logical truth is the generalised truth of propositions, the logic inherent in certain statements. It is arrived at by deductive and inferential processes, the capacity of language to reflect what is typical in nature as experienced by humanity. Much of the law is concerned with finding the connections between microscopic truth and logical truth.
Third, experiential truth is of a different order. It is the understanding gained from being inside and part of a phenomenon. It is the truth we are exposed to by living through a particular experience. I came across the concept when reading MK Gandhi's My experiments with Truth. Gandhi was testing himself, not an idea or the world out there. Such experiential truth is profound. Yet it embarrasses us in courts of law. We claim all we want is the objective truth, what we call "the facts".
Finally, there is what I call dialogical truth. We all have different experiences of reality, and diverse interests and backgrounds that influence the meaning of experiences for ourselves. The debate between many contentions and points of view goes backwards and forwards, and a new synthesis emerges, is challenged, controverted, and a fresh debate ensues. The process is never-ending, there is no finalised truth.
The strength of the Truth Commission is that it was based essentially on dialogue, on hearing all the different viewpoints, on receiving inputs from all sides. So the commission did not begin with the archive. The truth emerged lava-like, and congealed for posterity to end petrified in its limited but undeniable way in the archive.