The modern synthesis or evolutionary theory of aging assumes that aging results from the accumulation of errors or damages at the cellular level through the inadequacies of an organism's repair and maintenance machinery. The demonstration of cellular and organic rejuvenation requires the hypothesis that aging is the result of irreparable damage to be rejected. I will propose basic principles of mammalian aging based only on experimental data, without imposing the constraints of evolutionary theory. Consideration of the results of experiment suggests that fundamental assumptions about cell and organ aging being autonomous process, and about the centrality of cellular aging in organismic aging are wrong. The derived principles indicate that exogenous control of age-phenotype at cellular and higher levels of biological organization is possible.