International audience Since the time of Aristotle, the method of scientific knowledge consists inderivin singular cases from a universal proposition, after the universalproposition has been extracted as an invariant of a set of particular situations.Teilhard de Chardin practiced this method, but he also knew its limits. Themain limitation of the scientific method is that it has nothing to say about"phenomenal consciousness", about pure experience, about such exceptionalfact that only occurs in the first person singular.To tackle phenomenal consciousness, Teilhard de Chardin then reverses theorder of scientific deductions. The only way to approach consciousness,according to him, is to ‘discover the universal under the exceptional’. Thisstrategy leads him to grant a cosmic extension to consciousness, in the nameof its being absolutely obvious and primary for each of us. The validity ofthis reversed method is evaluated, after comparison with its equivalent inBergson, Whitehead, Ruyer, and Merleau-Ponty. Teilhard de Chardin’sconclusion is distinguished from contemporary panpsychism.