This study compares and contrasts Freud`s "work of mourning" which mostly appears in his memorable essay "Mourning and Melancholia" and Derrida`s theory of mourning which appears in various works such as MEMOIRES for Paul de Man, The Work of Mourning, and others. Freud maintains that the mourner begins to sever emotional ties to the lost object through a labor of memory and eventually completes the work of mourning. It is a "testing of reality" that motivates the mourner to begin to relinquish emotional attachment to the lost object. Derrida, however, challenges Freudian work of mourning by saying that true mourning lies in "respecting the Otherness of the Other," Derrida suggests that Freud`s "normal work of mourning" is "unjust betrayal" of the lost object because it "kills" and "devours" the other and thereby makes it part of the self. So he proposes that work of mourning has "to fail in order to succeed": "success fails" and "failure succeeds," There is an enormous, even epistemological, chasm between Freud who states that mourning, "however painful it may be, comes to a spontaneous end" and Derrida who states that "mourning is interminable, Inconsolable, Irreconcilable." and "I mourn Therefore I am," The former is the voice of "testing of reality" and common sense whereas the latter is that of utopian ethical vision. Yet neither seems to get the upper hand and they are kind of forced to maintain an ongoing dialogue with each other, for true mourning seems to lie somewhere in between.