Why is it the central teaching, and what does it teach? The 'truths' are just the same and just as fundamental in the Satikhya, the Yoga, the Nyaya systems and in medical science. There is very little Buddhistic in them. 1
I have pointed out that the four noble truths are not always a fundamental symbol of the Buddha's teachings in the Tipifaka. In contrast to their central role in most biographies of the Buddha, the four noble truths are set in relation to a variety of teachings at other points in the canon - teachings that include the four bases of mindfulness, dependent arising, the aggregates of grasping, the corruptions, the spheres of sense, and, in some places, nibbana. Where the four truths appear within these networks of teachings, they have a notably different role than their symbolic function. The four truths are not linked as explicitly to the Buddha's enlightenment, nor do they produce an experience of stream-entry through the acquisition of the dhamma eye.