I'm not sure the tautological is escapable... (at least I'm not sure that the tautology regarding the demand for freedom is escapable). The desire for freedom (which has two dialectical parts: freedom from external force and freedom from stupidity, otherwise known as enlightenment) comes out of wanting what one doesn't have. We desire freedom because we don't have it. This objective truth, however, is obscured by commodification and entrenched by the division of labour and means of production (we are proletarian, but we are not the proletariat) - the desire for freedom is replaced by various substitutes (desire is replaced by drive, which achieves satisfaction in consumption - the drive, of course, is circular - a kind of evil infinity of 'material' progress[!?]). However, this desire is rekindled whenever we experience injustice or alienation: the experience of alienated labour is the objective verification of the dialectical experience of domination and emancipation. The implication for an 'ethics of the Left' is this: desire is ethical. Capitalism certainly isn't handing out desire, whose object is imaginary - capitalism offers not desire but satisfaction and gratification (as false as it is, since an alienated self cannot find satisfaction through products produced under the conditions of alienated labour, hence, the circularity of drive / satisfaction). Desire, in effect, is precisely that which arrives from the viewpoint of the nonidentical, Lacan called this the object petit a.... it is ethical because it cannot be satisfied, which is why we can talk about the unfinished project of enlightenment, or, as Castoriadis puts it, the project of autonomy.
I'm sure I'm eventually going to get my knuckles rapped for mixing up Adorno, Castoriadis, Freud, Habermas and Lacan...
nothings wants something, ken