He--for there could be no doubt of his sex, though the fashion of the time did something to disguise it--was in the act of slicing at the head of a Moor which swung from the rafters. (1.1)
The first sentence of the novel clearly shows a direct action – "…was in the act of…" is quite explicit. This follows the traditional method of capturing a subject’s identity in a biography.
Orlando's fathers had ridden in fields of asphodel, and stony fields, and fields watered by strange rivers, and they had struck many heads of many colours off many shoulders, and brought them back to hang from the rafters. So too would Orlando, he vowed. But since he was sixteen only, and too young to ride with them in Africa or France, he would steal away from his mother and the peacocks in the garden and go to his attic room and there lunge and plunge and slice the air with his blade. (1.1 – 1.2)
Young Orlando longs to follow in the footsteps of his ancestors and slay foreigners. His life turns out rather differently. The Orlando at the end of the novel is a married woman with a successful career in poetry. What changed after this passage?
The long, curled hair, the dark head bent so reverently, so innocently before her, implied a pair of the finest legs that a young nobleman has ever stood upright upon; and violet eyes; and a heart of gold; and loyalty and manly charm. (1.11)
Orlando’s identity can be inferred from his physical appearance.
For though these are not matters on which a biographer can profitably enlarge it is plain enough to those who have done a reader's part in making up from bare hints dropped here and there the whole boundary and circumference of a living person; can hear in what we only whisper a living voice; can see, often when we say nothing about it, exactly what he looked like; know without a word to guide them precisely what he thought--and it is for readers such as these that we write--it is plain then to such a reader that Orlando was strangely compounded of many humours--of melancholy, of indolence, of passion, of love of solitude, to say nothing of all those contortions and subtleties of temper which were indicated on the first page, when he slashed at a dead n*****'s head; cut it down; hung it chivalrously out of his reach again and then betook himself to the windowseat with a book. (2.8)
We can extrapolate Orlando’s thoughts and feelings from "bare hints."
Orlando had become a woman--there is no denying it. But in every other respect, Orlando remained precisely as he had been. The change of sex, though it altered their future, did nothing whatever to alter their identity. Their faces remained, as their portraits prove, practically the same. His memory--but in future we must, for convention's sake, say 'her' for 'his,' and 'she' for 'he'--her memory then, went back through all the events of her past life without encountering any obstacle. (3.42)
This passage refutes the idea that Orlando’s identity changes after he becomes a woman. This passage encourages us to look elsewhere for the possible meaning and effects of the sex change, and hints that there may be none at all – although we think there are.
She had been a gloomy boy, in love with death, as boys are; and then she had been amorous and florid; and then she had been sprightly and satirical; and sometimes she had tried prose and sometimes she had tried drama. Yet through all these changes she had remained, she reflected, fundamentally the same. She had the same brooding meditative temper, the same love of animals and nature, the same passion for the country and the seasons. (5.14)
Here we have a more specific delineation of the ways in which identity is fluid and the ways in which it is not. Look at the specific details in this passage and try to build a portrait of exactly what can change in a person and what stays the same. How can she be amorous and florid while at the same time still being brooding?
No one showed an instant's suspicion that Orlando was not the Orlando they had known. If any doubt there was in the human mind the action of the deer and the dogs would have been enough to dispel it, for the dumb creatures, as is well known, are far better judges both of identity and character than we are. (4.21)
This dovetails nicely with the elevated place nature holds in Orlando. While humans may be fallible and inconstant, nature never is.
How she had loved sound when she was a boy, and thought the volley of tumultuous syllables from the lips the finest of all poetry. Then--it was the effect of Sasha and her disillusionment perhaps--into this high frenzy was let fall some black drop, which turned her rhapsody into sluggishness. […]She had formed here in solitude after her affair with Greene, or tried to form, for Heaven knows these growths are agelong in coming, a spirit capable of resistance. 'I will write,' she had said, 'what I enjoy writing'; and so had scratched out twenty-six volumes. Yet still, for all her travels and adventures and profound thinkings and turnings this way and that, she was only in process of fabrication. (4.27)
This passage first of all demonstrates that Orlando’s encounters with Sasha and Greene were important in the formation of his (or her) identity, and secondly it establishes that the person "Orlando" is still in the process of formation. Orlando’s subjectivity changes constantly.
So then one may sketch her spending her morning in a China robe of ambiguous gender among her books; then receiving a client or two (for she had many scores of suppliants) in the same garment; then she would take a turn in the garden and clip the nut trees--for which knee-breeches were convenient; then she would change into a flowered taffeta which best suited a drive to Richmond and a proposal of marriage from some great nobleman; and so back again to town, where she would don a snuff-coloured gown like a lawyer's and visit the courts to hear how her cases were doing,--for her fortune was wasting hourly and the suits seemed no nearer consummation than they had been a hundred years ago; and so, finally, when night came, she would more often than not become a nobleman complete from head to toe and walk the streets in search of adventure. (4.92)
By dressing as a man, Orlando explores different aspects of her identity. This connects well with the passage earlier in the chapter that argues clothes instead wear (or define) people. By donning different outfits, Orlando gives her different selves a physical manifestation and takes on different identities.
The names were different, of course, but the spirit was the same. Nick Greene had not changed, for all his knighthood. And yet, some change there was. […] He had grown plump; but he was a man verging on seventy. He had grown sleek: literature had been a prosperous pursuit evidently; but somehow the old restless, uneasy vivacity had gone. His stories, brilliant as they were, were no longer quite so free and easy. (6.29)
There is an essential spirit that does not alter even if centuries have passed.
Perhaps; but what appeared certain (for we are now in the region of 'perhaps' and ‘appears') was that the one she needed most kept aloof […] --as happens when, for some unaccountable reason, the conscious self, which is the uppermost, and has the power to desire, wishes to be nothing but one self. This is what some people call the true self, and it is, they say, compact of all the selves we have it in us to be; commanded and locked up by the Captain self, the Key self, which amalgamates and controls them all. Orlando was certainly seeking this self as the reader can judge from overhearing her talk as she drove. (6.73)
Although Orlando has many different selves, she has only one true self. Is she one true self by the end of the novel? How can we tell?
'What then? Who then?' she said. 'Thirty-six; in a motor-car; a woman. Yes, but a million other things as well. A snob am I? The garter in the hall? The leopards? My ancestors? Proud of them? Yes! Greedy, luxurious, vicious? Am I? (here a new self came in). Don't care a damn if I am. Truthful? I think so. Generous? Oh, but that don't count (here a new self came in). […] Trees, she said. (Here another self came in.) I love trees (she was passing a clump) growing there a thousand years. And barns (she passed a tumbledown barn at the edge of the road). And sheep dogs (here one came trotting across the road. She carefully avoided it). And the night. But people (here another self came in). People? (She repeated it as a question.) I don't know. Chattering, spiteful, always telling lies. (Here she turned into the High Street of her native town, which was crowded, for it was market day, with farmers, and shepherds, and old women with hens in baskets.) I like peasants. I understand crops. (6.74)
Look at how Woolf uses a combination of telling and showing to convey Orlando’s multiple selves and how they interact. This is a great example of stream of consciousness – as Orlando drives down a street, various images spark new selves and new memories.