With its careful attention to Justine’s condition, and especially with Dunst’s amazingly sensitive and nuanced performance, Melancholia refutes clinical objectivity, and instead depathologizes depression. For depression is all too often stigmatized as a moral or intellectual failure, a kind of unseemly self-indulgence — this seems to be John’s attitude towards Justine. Or else, at best, depression is understood reactively as a deficiency in relation to some supposedly normative state of mental health — this seems to be Claire’s attitude. But Melancholia suggests that both these positions are inadequate. By focusing attention so intensively upon Justine’s own emotions, it treats depression as a proper state of being, with its own integrity and ontological consistency. This is not the least of the film’s accomplishments.
I would go so far as to say that, in this regard, Melancholia is profoundly antiNietzschean[...] For Nietzsche has no empathy at all with the state of depression. Rather, he stigmatizes it in emphatically normative terms. Nietzsche insists upon “the futility, fallacy, absurdity, deceitfulness” of any “rebellion” against life. “A condemnation of life on the part of the living,” he writes, “is, in the end, only the symptom of a certain type of life.” Even the judgment that condemns life is itself “only a value judgment made by life”: which is to say, by a weak and decadent form of life. Nietzsche seeks to unmask all perspectives — even the most self-abnegating ones — as still being expressions of an underlying will to life. This universal cynicism is the inevitable counterpart of Nietzsche’s frequent, and strident, insistence upon the necessity of “cheerfulness.”
Contrary to all this, Justine’s will to life has been suspended. Her depression is a kind of positive insensibility or ataraxia, or even what Dominic Fox calls “militant dysphoria”. This is a state of being that no longer sees the world as its own, or itself as part of the world. As Fox puts it, “the distinction between living and dead matter collapses. The world is dead, and life appears within it as an irrational persistence, an insupportable excrescence”. Through its refusal to affirm or celebrate life, dysphoria subtracts itself from the will to power, and therefore from Nietzsche’s otherwise universal suspicion about motives. Depression is the one state that cannot be unmasked as just another expression of the will to power. The underlying assumption of Nietzsche’s entire critique of both morality and nihilism is that the human being, and indeed every organism, “prefers to will nothingness rather than not will”. But depression, at least in von Trier’s presentation of it, must be understood as a positive not-willing, rather than as a will to nothingness, or a destructive (and self-destructive) torsion of the will.
From Steven Shaviro's great esssay on Melancholia