The narcissist is sometimes perceived as whimsical, traitorous, posing and double crossing. The truth is that he is predictable and consistent. He follows one over-riding principle: the principle of Narcissistic Supply.

The narcissist had internalised a bad object. He feels corrupt, deserving to fail, to be disgraced and punished. He is forever surprised and thankful when good things happen to him. Out of touch with his own emotions and with his capabilities, he either exaggerates them or underestimates them.

He is likely to be grateful to his partner - and berate her! - for having chosen him to be her mate. Deep inside, he thinks that no one else would have been (or will be) as foolish, blind, or ignorant to have made this choice. The purported stupidity and blindness of his mate or spouse is substantiated by the very fact that she is his mate or spouse. Only a stupid and blind person would have preferred the narcissist, with his myriad deficiencies, to others.

This feeling of a "lucky break" is the true source of the asymmetry in the narcissist's relationships. The partner, having made this incredible choice to live with the narcissist (to bear this cross) is worthy of special consideration in compensation. The narcissist's willing partner - a rarity - warrants special treatment and a special (double) standard. The partner can be unfaithful, withholding (emotionally, financially), be dependent, be abusive, critical and so on - and, yet, be forgiven unconditionally.

This, no doubt, is the direct result of the narcissist's very flawed sense of self-worth and of an overpowering sense of inferiority.

This asymmetry is also an effective barrier against the expression of anger, even legitimate anger.

Instead, the narcissist accumulates his grievances every time that the partner takes advantage of the asymmetry (or is perceived by the narcissist to be doing so). The narcissist tries to convince himself that such abuse is an expected result of the daily friction of cohabitation, especially by partners with radically different personalities.

Some of the anger is passively-aggressively expressed. The frequency of sexual relations is reduced. Less sex, less talk, less touch. Sometimes the pent-up aggression erupts explosively in the form of rage attacks. These are usually followed by panicky reactions intended to restore the balance and to reassure the narcissist that he is not about to be abandoned.

Following such rage attacks, the narcissist regresses to passiveness, maudlin tenderness, appeasing gestures, or to wimpish, saccharine, and infantile behaviour. The narcissist does not expect or accept same behaviour from his partner. She is allowed to be cantankerous to her heart's content without as much as apologising.

Another hurdle on the narcissist's way to establishing lasting (if not healthy) relationships is his excess rationality and, chiefly, his tendency to generalise on the basis of tenuous and flimsy evidence (hyper-inductiviteness).

The narcissist regards abandonment or rejection by his emotional-sexual partners as a final verdict concerning his very ability to have such relationships in the future. Because of the mechanisms of self-denigration I have described, the narcissist is likely to idealise his mate and believe that she must have been uniquely predisposed and "equipped" to cope with him.

He "remembers" the way his partner sacrificed herself on the altar of the relationship. The more convinced the narcissist is that his partner invested extraordinarily in the relationship and the more assured he is that she was uniquely equipped to succeed in it - the more frightened he becomes.

Why the fear?

Because if this partner, as qualified as she was, as desirous of him as she was, failed to sustain the relationship - surely, no one else is likely to succeed. The narcissist believes that he is doomed to an existence of loneliness and destitution. He stands no chance of ever having a resilient, healthy relationship with another partner.

The narcissist would do anything to avoid this conclusion. He begs his partner to return and re-establish the relationship, no matter what transpired. Her very return proves to him that he is worthy, the preferred alternative, someone with whom maintaining a relationship is possible.

The partner, in other words, is the narcissist's equivalent of market research. That he was chosen by the partner is tantamount to receiving a quality award.

This dyad comprised of a "quality inspector" and a "chosen product" is only one of the pairs of roles adopted by the narcissist and his partner. Others include: "the sick" and "the healthy", "the doctor/psychologist" and "the patient", "the poor, underprivileged girl" and "the white knight in shining armour" dyads.

Both roles - the narcissist's and the one willingly (or unwillingly) adopted by the partner - are facets of the narcissist's personality. Through complex Projective Identification processes and other projective defence mechanisms the narcissist fosters a dialogue between parts of his self, using his partner as a mirror and a communication conduit.

Thus, by fostering such dialogs, the narcissist's relationships have a highly therapeutic value on the one hand. On the other hand they suffer from all the problems of a regime of psychotherapy: transference, counter-transference and the like.