It was more than a year later, in the Gilberts, that the explanation dawned upon myself. The natives were drawing palm-tree wine, a thing forbidden by law; and when the wind thus suddenly revealed them, they were doubtless more troubled than ourselves.

Here is an incident contained in a paragraph. Hindsight rounds the story off. The visual context, the island ambience, the culture clash are all there. And so is the author, taking a step back, looking at himself and his companions. The writer of first person documentary has to be observer, participant and artist. Stevenson highlights these roles by adopting a tone of mild irony, which also softens the nuts and bolts of his style, and maintains the distance between observer and actor. Twentieth-century writers would probably feel it was not so important to be scrupulous about distinguishing these roles, yet Stevenson’s control of tone gives a true modernity to his prose.

It is now around one hundred years since Stevenson was in the Pacific. From this distance we can see that he was engaged in one of the most important arenas of nineteenth-century history, both geographically and psychologically. We are now aware of the long-term effects of imperialism and are living with their consequences. What Stevenson witnessed, and what he recorded with considerable acuity, was colonialism in action in the Pacific one hundred years after the voyages of Captain Cook in the 1770s and 80s, a convenient date for locating the origins of imperialism in that part of the world.

Literary convention associates one great novelist in particular with the exploration and exposure of the tensions and conflicts inherent not just in the confrontation between imperialist powers and native populations, but in the sensations of the representatives of imperialism. This writer is Joseph Conrad, and his Heart of Darkness has become an emblem of the rotten core of exploitation. But a parallel and a companion to Conrad’s great novella can be found in the earlier and equally impressive story by Stevenson, The Beach of Falesá.

Stevenson saw the Pacific as a huge melting-pot, or perhaps ‘stew’ is a more appropriate word, remembering that he wrote about the islands as ‘a stir-about of epochs and races, barbarisms and civilisations, virtues and crimes’. He did not mean that these attributes belonged to one race or another. What his fiction tells us is that this ‘stir-about’ was a melange of peoples, none of which had any special claim to virtue or criminality. His particular interest, as it was Conrad’s later, was in the moral and psychological effects of an environment of exoticism and exploitation on people with differing backgrounds and assumptions.

All Stevenson’s fiction reveals a pre-eminent concern with the moral dimensions of man – of man in particular, rather than woman. Before coming to the Pacific he had examined moral ambivalence in the context mainly of Scotland’s past, although his most famous venture into this territory, Strange Case of Dr Jekyll and Mr Hyde, was ostensibly set in London. Scottish history offered event after event, situation after situation, which seemed to demonstrate and confirm what Stevenson saw as fundamental divisions within humankind, between emotional life and the instinct for survival – sometimes an instinct for evil – and the need for controlled social relations. Towards the end of his life he wrote to his cousin Bob, who had been a close companion of his experimental youth, ‘The prim obliterated polite face of life, and the broad, bawdy, and orgiastic – or maenadic – foundation, form a spectacle to which no habit reconciles me.’6 He did not have to search far in Scotland’s past to find extremes of feeling and belief, extremes that led to violence of action and language.

In spite of Jekyll and Hyde, where in fact the extremes of behaviour are not entirely convincing, Stevenson has not had the reputation of a writer engaged with violence. Yet we need look no further than Treasure Island or Kidnapped to find naked conflict starkly expressed. The adventure story genre of course accommodates violence quite comfortably. In The Master of Ballantrae it is rather more sinister. But physical violence is only one aspect of confrontation. In the unfinished Weir of Hermiston there is an attempt to illuminate the whole spectrum of division and extremity through one powerfully knotted plot. The bold language of the elder Kirstie warning the hero Archie about the dangers of his relationship with a young and vulnerable girl catches the essence of at least part of Stevenson’s concern. Kirstie’s words echo those of Stevenson’s to Bob.

Man, do ye no’ comprehend that it’s God’s wull we should be blendit and glamoured, and have nae command over our ain members at a time like that? My bairn … think o’ the puir lass! have pity upon her, Erchie! and O, be wise for twa! Think o’ the risk she rins! I have seen ye, and what’s to prevent ithers? I saw ye once in the Hags, in my ain howf, and I was wae to see ye there – in pairt for the omen, for I think there’s a weird on the place – and in pairt for puir nakit envy and bitterness o’ hairt. It’s strange ye should forgather there tae! God, but yon puir, thrawn, auld Covenanter’s seen a heap o’ human natur since he lookit his last on the musket-barrels, if he never saw nane afore …

Even without specific knowledge of the references here, to the Covenanting conflicts and martyrdoms for example, the vibrance of Kirstie’s language alerts us to many of the aspects of human feelings and behaviour that were a preoccupation during Stevenson’s years at Vailima. On the one hand there was human nature, willed by God, as the Calvinists believed, to lead to sin unless kept in check. On the other hand were the rules and rigid structures imposed to keep humanity under control, but which themselves were dangerous in their capacity to distort.

Weir of Hermiston is set in eighteenth-century Scotland. Stevenson was living in late nineteenth-century Samoa.