In church two young people profess unshakable, undying love; they promise that, whatever happens, they will remain faithful to each other. In this manner they mortgage themselves, pledging their state of mind at the moment of pronouncing a solemn oath as security for a love that death alone will terminate.

Often enough this state of mind only lasts a few months or years, progressively weakening with the passing of time; the undertaking emotionally entered into at that moment endures nonetheless, imposing a behaviour foreign to the true nature of the partners, but one they cannot seek to change without awful consequences.

Such emotional undertakings are certainly not restricted to conjugal fidelity: our friendships are likewise tainted, together with everything from political convictions to less fundamental opinions on art or literature. The stress created by such unnatural discipline is often aggravated by guilt feelings because we find infidelity tempting and because we resist the temptation: a split takes place in the psyche.

Let us be clear as to what the real cause of the problem is. Why do we believe fidelity is founded on some psychological reality? It is because we have accepted the principle of an enduring ego. And I am not speaking of persistence beyond the grave, but from one second to the next. We like to say that it is the body that changes, that what we bear within us is, if not immutable, then at least capable of persisting unchanged, and that, if changes do take place there, they are weaknesses, even perhaps psychological dysfunctions.

It is true, however, that there is more tolerance for changes in attitude about works of art than those about people. So you have heard Beethoven's Pastoral Symphony too often? It is starting to bore you? Fine. But do not become too fickle; your musical caprices should keep certain bounds. You do not have to remain permanently attached to all the works you once loved: you are free to change your musical hatreds into loves and vice versa, so long as you at least keep an inviolable love for one composer. That person who is unfaithful to Tchaikovsky, to Mozart, even to Bach (Johann Sebastian, no less, may one's name be praised!), in a word, to all the loves of one's youth except, say, Cimarosa, such a person, I affirm, cannot be taken to task for musical whim. But if, in the silent court of his conscience, he pleads guilty to ceasing to love one of his friends, then it follows with a totally cerebral logic that he cannot continue to love himself either. The very source of self-esteem has been dried up.

Such are the differences between ethics and aesthetics: a work of art brings beauty, while a person is sacred?

Bullshit! Yes, sacred bullshit!

And what precisely is this ego that people wish to protect from any vagaries of temperament? A bundle of stimuli and motor responses with all the neurological activity these involve, it is a sounding box vibrating with the noises of the moment, noises consumed in silence as soon as others make themselves heard; or again, it's a tape recorder which, as it records afresh, provisionally erases everything hitherto transcribed. The ego is thus a state as ephemeral as the wishes and feelings it is composed of. It's not an entity persisting from cradle to grave: indeed, it is legion, having the plurality of the psychological moments of a lifetime; and one should speak, not of his ego, but of his egos.

When we think of our egos of yesterday or last year, we feel as though we were in the presence of a phenomenon that is both strange and yet quite familiar - strange in its contents of stale dreams; familiar in its container: it is we who have dreamed and decided thus. At least that is what we believe. Nonetheless, these dreams and decisions do not seem to depend on us or to belong to us: they give the impression of being generated in someone else's head and only creeping into our's by mistake. A thought like 'Yesterday I loved her' could very well be written as 'Yesterday X or Y loved her'.

To explain adequately the source of this weakness I will have to re-examine the ternary structure of the psyche, and, in order to do so, I will readapt the old terms of psychoanalysis.

It seems to me there are two consciousnesses, each chronologically determined. One belongs to the past and the other to the present; each, however contains its share of the subconscious - that submerged nine-tenths of the iceberg.

First there is the past consciousness or ego, which, together with its attendant subconscious element, the id, is as transitory and as plural as the nerve messages that produced it. Then there are the conscious and subconscious of the present, which are the ego and the id become actualised. However, this present ego has a very important function, which I am calling the witness. This (you can call it the superego) is in a state of perpetual or, to be more precise, continually repeated watchfulness. It is this witness which, through memory, compares states of consciousness both past and present.

It is indeed due to memory that this witness gives an illusion of continuity: it feels as if it has existed for years, as if it were part and parcel of all those other egos to whose existence it testifies. In this it is strongly abetted by what I shall call our hereness, that delusion according to which we believe that we share a common time-space continuum with all our other egos of the past. Now it is only through memory of course that the past does exist: therefore, this psychological component - the witness -, by feeble reflections of the past mirrored back to it by memory, gives us the impression that it has always existed: if we apprehend a 'past' event, it is, we think, because we experienced it, because we 'were there'. Nothing could be less true: at the most we receive mnemonic representations, for the old egos are all dead.

Thus the enduring witness, seeming forever to hold its court in the silence of recollection, provokes in us the fantasy according to which all these scattered egos, discrete moments of our psychic life, are nothing but one single ego subsisting through all vicissitudes. It is in this way that the witness can plead to infidelity, though it was not he that said, 'I love you,' in the first place and in the second the person he 'no longer loves' is not the same any more, having ceased to exist just as he has himself.

In this way we spend a great part of our lives suffering the pangs of remorse and shame that have no basis in psychological reality. We endeavour - for a chimera - to follow plans of conduct that are no longer ours and to revive feelings that are as coldly dead as the soup we had at our wedding breakfast.