The combination of marxist concepts with « spatialism » in geographical analysis has not given rise to any original form of marxist geography. In fact, Marx's lesson must be sought within his law of profit. From the latter, can be drawn the idea for a law of power based on the concepts of energy and information. To the same extent that the formula M-C-M' (money-commodity-money) can enliven economic geography, the formula l-E-l' (information-energy-information) should enliven political geography.