In an essay on the roles of authors in their books, Mary Shelley mused that those who allow their own personalities to appear in their works 'turn to the human heart as the undiscovered country'.  Shelley's own novel The Last Man offers a sustained meditation on the motif of 'the country of the human heart'. Its first sentence is, 'I am the native of a sea-surrounded nook, a cloud-enshadowed land, which, when the surface of the globe, with its shoreless ocean and trackless continents, presents itself to my mind, appears only as an inconsiderable speck in the immense whole; and yet, when balanced in the scale of mental power, far outweighed countries of larger extent and more numerous population'.  The narrator is the eponymous hero Lionel Verney, whose situation as the sole and, in his own eyes, the least interesting survivor of a group of brilliant and heroic friends exactly paralleled Mary Shelley's own; moreover, as the narrative unfolds, it becomes apparent that Adrian, the delicate, democratic intellectual, is modelled directly on Percy Shelley, and that the fickle, fiery, ambitious, and much-travelled Raymond is a portrait of Byron.  To that extent, it obviously is the territory of Shelley's own heart which is being mapped.
However, the language of this opening self-introduction does more than establish the beginnings of an identity for a particular character: it also sketches a more general cognitive process which involves experiencing the exterior world in terms of an interior mental map whose contours may often differ significantly from those of the 'real'. Richard S. Albright suggests that
Shelley's use of "I AM," (in small capitals), to begin Verney's narrative, suggests the ancient Hebrew name for God. Verney has created this history, his own as well as his country's, and in fact has created this entire world, symbolically dividing the waters from the land. His view of space is vast enough that England is a mere speck to him (when it presents itself to his mind) and his perspective of time is comparably vast. His "I am" affirmation also calls to mind Coleridge's concept of the imagination. 
Certainly we are made privy to the interaction of two scales and modes of being here: the narrator's native land is small and insignificant in comparison with what he knows as the totality of external reality, but bulks large not only in his own mental landscape but, he seems to imply, in the mental realm in general. In part, this generalising effect may be attributed to the fact that at the time when he writes Verney is, to the best of his knowledge, the sole survivor of humanity; consequently, what Verney thinks is indeed, in this specialised sense, what the whole of humanity thinks. However, the implication also seems to be that Britain looms large in the mental sphere because its inhabitants are—or were—distinguished by their collective attainments and predominance in that sphere. This is in line with the emerging ideologies of colonialism and empire which find clear reflection elsewhere in the text, but it also introduces us to an equally insistent feature of the novel, a stress on the power of the mind and on the subjectivity of perception.
This idea is further developed in the lines which immediately follow. Verney goes on to gloss his own remark with the assurance that
So true it is, that man's mind alone was the creator of all that was good or great to man, and that Nature herself was only his first minister. England, seated far north in the turbid sea, now visits my dreams in the semblance of a vast and well-manned ship, which mastered the winds and rode proudly over the waves. In my boyish days she was the universe to me. When I stood on my native hills, and saw plain and mountains stretch out to the utmost limits of my vision, speckled by the dwellings of my countrymen, and subdued to fertility by their labours, the earth's very centre was fixed for me in that spot, and the rest of her orb was as a fable, to have forgotten which would have cost neither my imagination nor understanding an effort.p. 11
There are a number of things of interest here. The initial aphorism bears distinct signs of indebtedness to Hamlet's proposition that 'There's nothing either good or bad but thinking makes it so';  its presence offers us a strong indication of the temper and mood of what is to follow. There are also some low-key but suggestively delineated gender relations sketched in this passage. Short as it is, it contains four separate vignettes of female subordination to the male. Nature, capitalised though she may be, is only man's minister; England (whose feminine gender is confirmed by the subsequent use of the pronoun 'she') is like a 'well-manned ship'—a passive, feminised vehicle for an expression of male power; the earth (again subsequently confirmed as feminine by the use of a pronoun) is 'subdued to fertility' by the labours of countrymen (my emphasis); and finally the whole 'orb' of the earth pales into insignificance in the lordly imagination of Verney.
In the daughter of Mary Wollstonecraft, attention to gender is hardly surprising, and the question of gender lies close to the heart of the book, for if, as so often, we interpret it as a roman à clef in which the memories of various members of the Shelley circle are enshrined, we cannot fail to notice that Mary herself appears not as a woman but a man. Perhaps her quadruple images of the feminine as disempowered in this opening paragraph offer some clue to this fictional transvestism, but equally it implies that there may well be a radical disjunction between gender roles as externally assigned and gender roles as internally experienced—not that I mean to suggest that Mary Shelley aspired to be male, but that she may have felt that, regardless of actual external gender, writing from a masculinised subject position carried superior authority, as is indeed suggested by the fact that the image of the boat is so prevalent in both the life and work of Percy Shelley that her use of it may stand as a clear act of appropriation. Similarly, the dizzying shifts of perspective here, as we follow in reverse order the move from a subjectivity which regards England as the centre of the universe to one that envisages it as peripherally located in the North, reinforce the opening's emphasis on the primacy of perception. 'Mind', 'dreams', 'imagination' and 'understanding' cluster together to confirm for us that in this novel, all landscape will be experienced primarily as the landscape of the heart.
The converse, however, is also true: not only do the characters of The Last Man experience the landscape around them in terms of their inner lives, they also experience their inner lives in terms of landscape. When Lionel's father feels his influence waning, instead of 'profiting by this last calm before the storm to save himself' he relies instead on the fact that 'his presence dissipated these clouds', only to find his friend the king exhorting him 'to spend his great powers on a worthy field' (p. 12). When this plan fails, and his father exiles himself, Verney recounts how '[a]sk where now was this favourite of fashion, this companion of the noble, this excelling beam, which gilt with alien splendour the assemblies of the courtly and the gay—you heard that he was under a cloud, a lost man' (p. 13). It is unsurprising that the daughter of such a man, Lionel's sister Perdita, 'never spoke until she had mingled her perceptions of outward objects with others which were the native growth of her own mind. She was like a fruitful soil that imbibed the airs and dews of heaven, and gave them forth again to light in loveliest forms of fruits and flowers; but then she was often dark and rugged as that soil, raked up, and new sown with unseen seed' (p. 17). Meanwhile his son, Verney himself—who significantly lives separately from Perdita, not on the 'gently' sloping banks of Ullswater but closer to the 'dark crag' (p. 17) above—finds that at the age of sixteen 'passions, strong as the trees of a forest, had already taken root within me, and were about to shadow with their noxious overgrowth, my path of life', so that '[t]hus I stood upon a pinnacle, a sea of evil rolled at my feet; I was about to precipitate myself into it, and rush like a torrent over all obstructions to the object of my wishes—when a stranger influence came over the current of my fortunes, and changed their boisterous course to what was in comparison like the gentle meanderings of a meadow-encircling streamlet' (pp. 18-9). Chthonic Perdita, like the Persephone with whom her namesake in The Winter's Tale is so strongly associated, is linked part of the time with fruit-bearing and the light, and part of the time with darkness and the unseen processes of germination; her brother's temperament is more phallically and actively figured in terms of tall trees and towering cliffs towards which he is rushing. Both, though, show equally the extent to which landscape in this novel is conceived of as constituting, conditioning and interpenetrating the subjectivity of the human beings who inhabit it.
At the same time, however, we are made powerfully aware that the process is not only one way. A relatively small variation in physical location—separate dwellings on the shores of the same lake—is reflected as major psychic differences between Lionel and Perdita. From this we conclude that human beings are not simply the product of their physical environment; other factors, such as temperament and perhaps gender, must also play a part. In this novel about the predicament of the sole survivor of a once-flourishing social group, Mary Shelley has thus found in the interplay of interior and exterior landscape a telling model for the interaction of the individual and society, something in which she differs notably from the other contemporary writers who tackled the Last Man theme. 
Landscape thus becomes the perfect metaphor for the process which is central to this novel, the charting of the ways in which human beings are affected and conditioned by the attitudes and actions of other human beings, as when Lionel writes of frivolous people that 'sharp rocks lurk beneath the smiling ripples of these shallow waters' (p. 33). In one sense, it is necessary in narrative terms for Mary Shelley to establish a strong sense of this interaction for us to feel to the full the dreadfulness of Lionel's ultimate solitude. Equally, though, this sense of humans as fundamentally social is central to all her novels, not just this one, and seems to have formed a crucial part of her personal philosophy, as indeed was to be expected of the daughter of two such social theorists as Godwin and Wollstonecraft. Thus when Lionel first meets Adrian, he notes that 'his appearance blew aside, with gentle western breath, my cloudy wrath: a tall, slim, fair boy, with a physiognomy expressive of the excess of sensibility and refinement stood before me; the morning sunbeams tinged with gold his silken hair, and spread light and glory over his beaming countenance' (p. 23). The effect of one personality on another is thus imaged as a beneficent weather effect, but this action is in turn dependent on the operation of an an actual beneficent weather effect, suggesting that the psychological does not float free from the material environment.
Indeed we are soon explicitly told that apprehension of the internal landscape must go hand-in-hand with apprehension of the external, as Lionel records:
curiosity soon awoke, and an earnest love of knowledge, which caused me to pass days and nights in reading and study. I was already well acquainted with what I may term the panorama of nature, the change of seasons, and the various appearances of heaven and earth. But I was at once startled and enchanted by my sudden extension of vision, when the curtain, which had been drawn before the intellectual world, was withdrawn, and I saw the universe, not only as it presented itself to my outward senses, but as it had appeared to the wisest among men.p. 27
This discovery of the landscape of the mind which lies behind the physical landscape makes Lionel feel 'as the sailor, who from the topmast first discovered the shore of America; and like him I hastened to tell my companions of my discoveries in unknown regions', because 'I had lived in what is generally called the world of reality, and it was awakening to a new country to find that there was a deeper meaning in all I saw, besides that which my eyes conveyed to me'. The result of such a change is to '[alter] the reflection of the apparent universe in the mirror of mind' (p. 27). What is notable here is the insistence on the interdependence of exterior and interior landscapes: neither has primacy (the world of reality is clearly presented as a construct rather tthan an absolute), and neither, it seems, has any validity when it is separated from the other. It is also worth remarking that, as in the later Lodore, America stands for Mary Shelley as a symbol of freedom, as when, under the influence of Adrian, a royal who would enfranchise would-be republics rather than cling to them, Lionel finds that '[f]riendship...built a bower of delight in my heart, late rough as an untrod wild in America, as the homeless wind or herbless sea', so that his happiness is 'unclouded' (p. 31).
Disaster lurks, however, for those who lose sight of the fact that exterior and interior must work in tandem. When Adrian falls in love with Evadne, he allows the interior landscape of his heart to become all-encompassing:
The universe was to him a dwelling, to inhabit with his chosen one; and not either a scheme of society or an enchainment of events, that could impact to him either happiness or misery. What, though life and the system of social intercourse were a wilderness, a tiger-haunted jungle! Through the midst of its errors, in the depths of its savage recesses, there was a disentangled and flowery pathway, through which they might journey in safety and delight. Their track would be like the passage of the Red Sea, which they might traverse with unwet feet, though a wall of destruction were impending on either side.pp. 29-30
To Adrian, external and internal landscapes are no longer working in harmony: the exterior world is virtually as bad as it can be, a tiger-haunted jungle, but the interior landscape is a 'flowery pathway' positively Spenserian in its delusive attractiveness. Indeed Adrian's psyche divorces literal and metaphorical landscapes so comprehensively as metaphorically to misrecognise land as water—and the result, unsurprisingly, is ultimately madness, tellingly imaged as a climatic disharmony in which Adrian's soul was 'stript...of its leaves ere winter-time' (p. 37). (It also echoes the opening of the novel, where what was formerly landscape has now become seascape.)  In the view of the narrator, this is primarily because 'disappointment is the never-failing pilot of our life's bark, and ruthlessly carries us on to the shoals' (p. 30). Whether it is Lionel Verney or Mary Shelley herself who is imagined as speaking here, either certainly has just cause to complain of the cruelty of the sea, making Adrian's idea that he is safe from its power all the more poignant (especially since he is so obviously the fictional alter ego of the drowned Percy Shelley). By instinct, Adrian would steer a moderate course, because 'concealment or deceit were at the antipodes to the dreadless frankness of his nature' (p. 30), but once one is launched on the sea one loses control of one's direction.
Equal danger, however, lies in the other direction, that taken by Raymond, who 'looked on the structure of society as but a part of the machinery which supported the web on which his life was traced. The earth was spread out as an highway for him; the heavens built up as a canopy for him' (p. 38). As so often for Mary Shelley, moderation is the key, and here she falls back on the long-established image of a literal landscape to emblematise it; indeed Evadne loves Raymond almost as a manifestation of the Greek 'clime' (p. 39), while Lionel himself, Shelley's own fictional alter ego, declares that '[tlhe spirit of Idris hovered in the air I breathed' (p. 51). Similarly Raymond seems directly to pay tribute to the harmony of interior and exterior in Lionel when he calls him '[y]ou, who fancy that you can read the human soul, as your native lake reads each crevice and folding of its surrounding hills', while he himself feels a disastrous imbalance between his external circumstances and his internal response to them (pp. 52-3).
Ironically, too, it is Raymond who offers the most detailed analysis of the motif of correlation, but he does so purely as an intellectual exercise:
Philosophers have called man a microcosm of nature, and find a reflection in the internal mind for all this machinery visibly at work around us. This theory has often been a source of amusement to me; and many an idle hour have I spent, exercising my ingenuity in finding resemblances...What a sea is the tide of passion, whose fountains are in our own nature! Our virtues are the quick-sands, which shew themselves at calm and low water; but let the waves arise and the winds buffet them, and the poor devil whose hope was in their durability, finds them sink from under him. The fashions of the world, its exigencies, educations and pursuits, are winds to drive our wills, like clouds all one way; but let a thunderstorm arise in the shape of love, hate, or ambition, and the rack goes backward, stemming the opposing air in triumph.pp. 54-5
For Raymond, tracing such correlations is, he declares, merely a source of amusement, although his own present state of slavery to passion may also hint that more is at stake. Lionel, characteristically, takes them more seriously, and proposes an important inflection of the model of one-to-one correspondence:
"Yet," replied I, "nature always presents to our eyes the appearance of a patient: while there is an active principle in man which is capable of ruling fortune, and at least of tacking against the gale, till it in some mode conquers it."p. 55
For Lionel, there is a crucial distinction: nature is purely passive, but man has at least partial agency. Here we are back on the philosophical terrain of Frankenstein, where Victor's preferred use of the passive voice makes a consistent play to persuade us into an ideological position in which we regard him not as morally responsible for his actions but as victimised by fate.  Moreover, the vehicle as well as the tenor reprises the ideas of Frankenstein, because Victor so often commits himself and his fortunes to actual boats, whether on Lake Geneva, the Irish Channel, or the Arctic Ocean. Lionel, however, will not capitulate to the doctrine of Necessity: for him the human mind does not simply offer a microcosm or mirror of the world without, but surpasses it because humanity is capable of resistance. Even so, Lionel, in keeping with the passivity which marks his character after Adrian has tamed his initial rebelliousness, takes no personal credit for this. Indeed he phrases his qualification in a way so guarded that the grammar very nearly undoes the force of the individual words. '[T]here is an active principle in man which is capable of ruling fortune, and at least of tacking against the gale, till it in some mode conquers it': man is here envisaged as little more than the passive host of this active principle, and it is the principle rather than the man which governs the verbs which follow.
Even thus severely qualified, however, Lionel's assertion is too much for Raymond:
"There is more of what is specious than true in your distinction," said my companion. "Did we form ourselves, choosing our dispositions, and our powers? I find myself, for one, as a stringed instrument with chords and stops— but I have no power to turn the pegs, or pitch my thoughts to a higher or lower key."p. 55
Raymond here strikes still another note germane to Frankenstein: he presents himself as a creature, something which did not form itself and consequently cannot be held responsible for his actions. His metaphor of the untuned instrument further works to suggest that while Raymond may be a creature, his world, like that of Frankenstein, definitively lacks a divine creator. For Raymond, though, it lacks more than that, for when Lionel ripostes that 'Other men...may be better musicians' (p. 55), Raymond replies 'I talk not of others, but myself' (p. 55). This solipsism, with its entire disregard for the impact and influence of the others which the motif of the landscape of the heart has served so far to emblematise, sums up Raymond's attitude throughout, and it is precisely what Mary Shelley, not only here but in all her novels, most condemns. The prime thrust of her consistent use of the motif of interior and exterior correspondences is precisely to demonstrate the dangerous falsity of Raymond's proposition, and this one exchange enacts the entire dynamic and consequences of his ideological stance no less clearly than does the overall structure of the narrative as a whole.
Equally important for Mary Shelley is her idea that people must be aware not only of how they interact with others, but also that, to a certain extent, they have others inside them. Although the flatness of portraits like Lady Katherine Gordon in The Fortunes of Perkin Warbeck has led many critics to allege that she is a poor creator of character, it is clear that, whatever the execution, character in Mary Shelley's imagination is invariably conceived of as something dynamic and complex rather than static and simple. Perdita's love for Raymond, for instance, is described as follows:
His kingdom was the heart of Perdita, his subjects her thoughts...She erected a temple for him in the depth of her being, and each faculty was a priestess vowed to his service. Sometimes she might be wayward and capricious; but her repentance was bitter, her return entire, and even this inequality of temper suited him who was not formed by nature to float idly down the stream of life.p. 74
Similarly, Adrian opines:
I know now that I am not a man fitted to govern nations; sufficient for me, if I keep in wholesome rule the little kingdom of my own mortality.p. 77
Adrian's is soon shown to be the true wisdom as the first of their many disasters looms over the little band of friends when Raymond encounters Evadne again:
Thus, while Raymond had been wrapt in visions of power and fame, while he looked forward to entire dominion over the elements and the mind of man, the territory of his own heart escaped his notice; and from that unthought of source arose the mighty torrent that overwhelmed his will, and carried to the oblivious sea, fame, hope, and happiness.p. 93
His carelessness will take him into a troubled emotional countryside in which Perdita, who has always been so sensitive to 'the universe within' (p. 123), stands on an invisible precipice and a stream flows between them (p. 98), and where she feels herself chained to a rock in the middle of a desert (p. 106), cast adrift to find that 'her own character...became the first in rank among the terrae incognitae, the pathless wilds of a country that had no chart' (p. 123-4).
Soon enough, of course, all the characters find themselves in such a world. Even when the plague strikes, however, it is human reaction and interaction that remain at the forefront of the narrative interest. Lionel registers the plague with less horror than he does some of the responses to it:
these smaller and separate tragedies were about to yield to a mightier interest—and, while we were promised calm from infectious influences, a tempest arose wilder than the winds, a tempest bred by the passions of man, nourished by his most violent impulses, unexampled and dire.p. 230
Moreover, it is loss in the human sphere that proves the worst part of Lionel's nightmare: with the solitary exception of Old Martha, he is actually the only human being to catch the plague and make a full recovery from it, but his survival becomes a curse rather than a blessing when he is left without any companions. When Mary Shelley's novel opens with a descent into a cave, so reminiscent of the extended description in Valperga of the human mind as a cave,  we may expect it to focus primarily on the psychological, and this is what it does. This, indeed, is where the heart of its meaning lies, in ways that have not always been perceived. The Hogarth Press edition of the novel has an introduction by Brian Aldiss, the noted science fiction writer, and The Last Man, like Frankenstein, has indeed often been received as science fiction or as science-oriented prophecy (as in the recent critical tendency to read it in terms of the AIDS epidemic).  The two novels have, moreover, suffered from what one might well see in both instances as the curse of topicality: any new scientific scare is sure to evoke the mention of Frankenstein (witness the recent tabloid labelling of genetically modified products as 'frankenfoods'), and The Last Man's prediction of the downfall of the house of Windsor may well appear more uncannily accurate with every passing day. However, to focus on these aspects of the books alone distorts the fact that at their heart lie the concerns not of our time, but of Mary Shelley's own: they are not eerie prophecies of heart transplants or of Camilla Parker Bowles, but passionate, articulate, informed, and intensely personal responses to the individualist ethos of Romanticism which Mary Shelley had had all too many opportunities to observe at first-hand. In her hands, the already well-established topos of the last man becomes not a simple fantasy of apocalypse but a sustained and complex plea for a proper mode of living which takes full account of all the other beings who make up the community of which the individual is, and must remain, inextricably part. For her, to wander lonely as a cloud is hell, and to seek to transcend or ignore society folly. It is too late for Lionel, just as it was for Mary Shelley herself, but it is not too late for their joint voices to reach out in a terrible warning to others.
For quotation of this phrase, and consideration of it in relation to Mary Shelley's own travel writing, see Clarissa Campbell Orr, 'Mary Shelley's Rambles in Germany and Italy, the Celebrity Author, and the undiscovered country of the human heart', Romanticism on the Net 11 (August, 1998) <http://www.erudit.org/revue/ron/1998/v/n11/005813ar.html>.
Mary Shelley, The Last Man, eds. Jane Blumberg with Nora Crook (London: William Pickering, 1996) p. 11. All further quotations from the novel will be taken from this edition and reference will be given in the text.
For comment on the autobiographical nature of the novel, see for instance Muriel Spark, Mary Shelley  (London: Sphere, 1989) pp. 180-2, and Paul A. Cantor, 'The Apocalypse of Empire: Mary Shelley's The Last Man', in Iconoclastic Departures: Mary Shelley after Frankenstein, eds. Syndy M. Conger, Frederick S. Frank, and Gregory O'Dea (London: Associated University Presses, 1997) p. 201. For a rather differently inflected discussion, see John Williams, Mary Shelley: A Literary Life (Basingstoke: Macmillan, 2000) pp. 112-3.
Richard S. Albright, '"In the mean time, what did Perdita?": Rhythms and Reversals in Mary Shelley's The Last Man', Romanticism on the Net 13 (February 1999) <http://www.erudit.org/revue/ron/1999/v/n13/005848ar.html>.
William Shakespeare, Hamlet, ed. Harold Jenkins (London: Methuen, 1982) II.ii.249-50.
See for instance Fiona Stafford, The Last of the Race: The Growth of a Myth from Milton to Darwin (Oxford: The Clarendon Press, 1994) pp. 199 and 216, and Jane Blumberg, Mary Shelley's Early Novels (Basingstoke: Macmillan, 1993) p. 124.
I am indebted for this observation to one of the anonymous readers of the first draft of this article, who also pointed out Percy Shelley's trait of describing a landscape as if it were a seascape.
On Frankenstein's passivity, see for instance Mary K. Patterson Thornburg, The Monster in the Mirror: Gender and the Sentimental/Gothic Myth in Frankenstein (Michigan, 1984; reprinted, 1987) p. 105, Mary Poovey, 'My Hideous Progeny: Mary Shelley and the Feminisation of Romance', Publications of the Modern Language Association of America, 95 (1980), reprinted in The Gothick: A Casebook, ed. Victor Sage (Basingstoke: Macmillan, 1993) p. 172, and Philip Stevick, 'Frankenstein and Comedy', in The Endurance of Frankenstein, eds. by George Levine and U.C. Knoepflmacher (Berkeley and Los Angeles, 1979) p. 237. Anne K. Mellor, however, remarks on the fact that Frankentein's passivity in this respect is much more marked in the revised text of 1831 than in the original 1818 version (Mary Shelley: Her Life, Her Fiction, Her Monsters [London and New York, 1988] pp. 170-1).
Mary Shelley, Valperga: or, the Life and Adventures of Castruccio, Prince of Lucca, 3 vols. (London: G. and W.B. Whittaker, 1823) vol. III, pp. 99-102.
See for instance Cantor, 'Apocalypse of Empire', p. 194, and Audrey A. Fisch, 'Plaguing Politics: AIDS, Deconstruction, and The Last Man', in The Other Mary Shelley: Beyond 'Frankenstein', eds. Audrey A. Fisch, Anne K. Mellor, and Esther H. Schor (Oxford: Oxford University Press, 1993) pp. 267-86.