The concept of “hegemony” in political thought has different philosophical-theoretical foundations and semantic dimensions. This concept should not be perceived merely and necessarily in a way which discloses another ways of perception. This concept should not be perceived in a way which traps us in the abyss of metaphysical disclosure. There is not one way of perception which overcomes other alternatives. Therefore, this article deconstructs this tendency to “the One” and lightens the way of perceiving this concept in “one of the possible ways”. Hence, this article concentrates on the political thought of Ernesto Laclau and hereby probes the philosophical foundations of this concept in the philosophy of Jacques Derrida and reveals the signifiers which construct the articulation of this concept as its semantic dimensions. As we will see, the mentioned signifiers are articulated among a master signifier or a nodal point which is contingency of hegemony. “The undecidable” and “the untouchable” are two Derridean concepts which are the philosophical foundations of these signifiers. However, this contingency does not mean inaccuracy or instability or lack of an ontological basis. Therefore, the contingency, undecidability and untouchability of hegemony should be understood as lack of an "ultimate foundation" and not "the foundation". Contingency and lack of an ultimate foundation have relationship with the aporetic nature of hegemony and its presence in the absence and its absence in the presence.