Slavoj Žižek, answered from the texts and cited to the page.
The key is this: there is nothing intrinsically sublime about a sublime object.1 That is the whole point, and it is the point that ideology theory before Lacan consistently missed. What makes an object sublime is not some special inner quality, some luminous property residing in the thing itself — it is purely structural, a matter of place. A sublime object is an ordinary, everyday object which, quite by chance, finds itself occupying the place of what Lacan calls das Ding, the impossible-real Thing, the void at the center of desire.1
It is its position — the fact that it occupies the sacred, forbidden place of jouissance — that confers sublimity upon it, nothing else.2 To understand this, we need the Kantian background. For Kant, the Sublime names the paradoxical relation between an empirical, sensuous object and the transcendent Thing-in-itself. The gap between phenomenal experience and the Ding an sich is in principle insurmountable — no empirical object can adequately present the suprasensible Idea — and yet the Sublime is precisely an object in which we can experience this very impossibility, this failure of representation to reach the Thing.3
The pleasure and displeasure arrive simultaneously: displeasure because the object is inadequate to the Thing, pleasure because through that very inadequacy we get a presentiment of the Thing's incomparable greatness.3 The phenomenon's inability to represent the Thing is inscribed in the phenomenon itself — the Sublime is the successful presentation of failure.4
Lacan takes this structure and materializes it. What the sublime object masks by its massive, fascinating presence is not some other positivity lurking behind it — it is masking its own place, the void, the lack.5 The place logically precedes the objects that occupy it; what those objects cover over is simply the emptiness they are filling out.6
This is why the sublime object can persist only at a certain distance, in an interspace, half-seen — if you approach it too closely, it loses its sublime features entirely and becomes an ordinary vulgar thing, because in itself it is nothing at all.7 Think of Fellini's workers in Roma who break through into a buried Roman chamber and find walls covered with magnificent frescoes — but the moment open air reaches them, the paintings dissolve, leaving only blank walls.7
Buñuel understood this before the theorists did. In film after film — The Exterminating Angel, The Discreet Charm of the Bourgeoisie, That Obscure Object of Desire — the same structure repeats: an entirely ordinary act (a dinner, crossing a threshold, a sexual reunion) becomes impossible to accomplish the moment it occupies the place of das Ding.8
The act is not blocked by some powerful external force; it is blocked by its own elevation to the impossible place of the Thing. In its very vulgarity, it cannot be reached.8 Now — the ideology. An ideological object, a Nation, a Leader, a Cause, operates by exactly this mechanism. It is an ordinary historical formation — a piece of contingent social reality — that has come to occupy the sacred place, to embody what Lacan calls the lack in the Other, in the symbolic order itself.9
The Real, in its positivity, is nothing but an embodiment of a pure negativity, an emptiness — and the sublime object of ideology is the object that fills that emptiness, that gives body to the void.9 This is why ideological attachment has the structure of jouissance rather than mere belief: you do not simply believe in the Nation as a useful social fiction; you enjoy it, you suffer for it, you find in it the impossible Thing that organizes your desire.
And this is precisely why ideological critique that merely demonstrates the constructed, contingent character of the ideological object so consistently fails — people know the Nation is a historical construction, and they go on treating it as the Thing anyway. The knowledge does not dissolve the attachment, because the attachment is not epistemic. It is structural.
We must remember that there is nothing intrinsically sublime in a sublime object — according to Lacan, a sublime object is an ordinary, everyday object which, quite by chance, finds itself occupying the place of what he calls das Ding, the impossible-real object of desire.The Sublime Object of Ideology, p. 252
It is its structural place - the fact that it occupies the sacred/forbidden place of jouissance - and not its intrinsic qualities that confers on it its sublimity.The Sublime Object of Ideology, p. 252
The feeling of the Sublime is, therefore, at once a feeling of displeasure, arising from the inadequacy of imagination in the aesthetic estimation of magnitude to attain, to its estimation by reason, and a simultaneously awakened pleasure, arising from this very judgement of the inadequacy of the greatest faculty of sense being in accord with ideas of reason.The Sublime Object of Ideology, pp. 260–261
the Sublime is therefore the paradox of an object which, in the very field of representation, provides a view, in a negative way, of the dimension of what is unrepresentable... the phenomenon's very inability to represent the Thing adequately is inscribed in the phenomenon itself.The Sublime Object of Ideology, pp. 260–261
What the object is masking, dissimulating, by its massive, fascinating presence, is not some other positivity but its own place, the void, the lack.The Sublime Object of Ideology, p. 252
the place logically precedes objects which occupy it: what the objects, in their given positivity, are masking is not some other, more substantial order of objects but simply the emptiness, the void they are filling out.The Sublime Object of Ideology, p. 252
The sublime object is an object which cannot be approached too closely: if we get too near it, it loses its sublime features and becomes an ordinary vulgar object... Let us take a well-known scene from Fellini's Roma: the workers digging tunnels for a subway find the remnants of some old Roman buildings... a marvellous view awaits them: walls full of beautiful frescos... but the paintings are too fragile, they cannot withstand the open air and immediately begin to dissolve, leaving the spectators alone with the blank walls.The Sublime Object of Ideology, pp. 223–224
An act becomes impossible to accomplish as soon as it finds itself occupying the impossible place of das Ding and begins to embody the sublime object of desire... It has only to occupy the sacred/forbidden, empty place in the Other, and a whole series of impassable obstacles will build up around it.The Sublime Object of Ideology, p. 252
the Real itself, in its positivity, is nothing but an embodiment of a certain void, lack, radical negativity... That is why the real object is a sublime object in a strict Lacanian sense - an object which is just an embodiment of the lack in the Other, in the symbolic order.The Sublime Object of Ideology, pp. 223–224