Was leaving his true thoughts lying around where she was bound to find them his way of telling her what he was too cowardly to say to her face? What are his true thoughts anyway? Some days he feels happy, even privileged, to be living with a beautiful woman, or at least not to be living alone. Other days he feels differently. Is the truth the happiness, the unhappiness, or the average of the two?
The question of what should be permitted to go into his diary and what kept forever shrouded goes to the heart of all his writing. If he is to censor himself from expressing ignoble emotions -- resentment at having his flat invaded, or shame at his own failures as a lover -- how will those emotions ever be transfigured and turned into poetry? And if poetry is not to be the agency of his transfiguration from ignoble to noble, why bother with poetry at all? Besides, who is to say that the feelings he writes in his diary are his true feelings? Who is to say that at each moment while the pen moves he is truly himself? At one moment he might truly be himself, at another he might simply be making things up. How can he know for sure? Why should he even want to know for sure?
Things are rarely as they seem: that is what he should have said to Jacqueline. Yet what chance is there she would have understood? How could she believe that what she read in his diary was not the truth, the ignoble truth, about what was going on in the mind of her companion during those heavy evenings of silence and sighings but on the contrary a fiction, one of many possible fictions, true only in the sense that a work of art is true -- true to itself, true to its own immanent aims -- when the ignoble reading conformed so closely to her own suspicion that her companion did not love her, did not even like her?
Jacqueline will not believe him, for the simple reason that he does not believe himself. He does not know what he believes. Sometimes he thinks he does not believe anything. But when all is said and done, the fact remains that his first try at living with a woman has ended in failure, in ignominy.
And the second:
Her story, spoken night after night in overlapping and conflicting versions into his sleep-befuddled ear, is that she has been robbed of her true self by a persecutor who is sometimes her tyrannical mother, sometimes a Mephistophelean therapist. What he holds in his arms, she says, is only a shell of her true self; she will recover the power to love only when she has recovered her self.
I don't think there's much commentary needed. The character who is in some sense Coetzee is very uncertain about his beliefs and even, perhaps, the concept of belief. The character who clearly has mental health problems believes in the self in a way that Coetzee seems very skeptical about. Whether he's right is another matter, of course, but perhaps the novel will show to what extent he is. There is something like Hume's bundle theory of the self here, but expressed much more tentatively and subjectively than Hume's theory is presented. That is, Hume speaks quite confidently about all people as if he is reporting well-established psychological findings. Coetzee, on the other hand, struggles to express how he feels or experiences his life. He makes no claims about other people, nor even anything definite about himself.