You may or may not have read Sapiens: A Brief History Of Humankind, a bestselling book by a historian called Yuval Noah Harari. It came out in 2015 and did a pretty readable job of assembling a timeline of the entirety of human history, although a few eminent reviewers have described it as flawed. One of the more profound points that Harari makes in Sapiens is that human happiness is pretty much predetermined at birth by our brain chemistry. We're dished out a certain amount of serotonin, the 'happy hormone', by our genes, and nothing that happens to us in our lives can significantly raise or lower our happiness level beyond a relatively brief period.

Another cheerful theme of Sapiens is life's essential meaninglessness. Millennia of scientific research have failed to discover a solid, verifiable reason why the human race exists. However, as self-aware creatures we yearn for our lives to have meaning, so we have a problem. Some of us find a solution by creating our own meaning, perhaps by worshipping a supernatural deity, or making money, or doing something that is mutually agreed to be morally good, or simply by propagating the species.

Whatever meaning you find in your personal trajectory between womb and tomb, it tends to be rewarded with feelgood brain chemicals. Alcohol and drugs provide a shortcut to the exact same chemicals. Arguably, those chemicals are the meaning we're after. All routes take the same path towards the same goal, and all are equally pointless, concludes Sapiens. Hey thanks, Yuval.

A similar point with a different emphasis was made by the late film director Stanley Kubrick, who told Playboy magazine in 1968:

''The very meaninglessness of life forces man to create his own meaning. Children, of course, begin life with an untarnished sense of wonder, a capacity to experience total joy at something as simple as the greenness of a leaf; but as they grow older, the awareness of death and decay begins to impinge on their consciousness... As a child matures, he sees death and pain everywhere about him, and begins to lose faith in the ultimate goodness of man. But, if he's reasonably strong - and lucky - he can emerge from this twilight of the soul... in spite of his awareness of the meaninglessness of life, he can forge a fresh sense of purpose and affirmation. He may not recapture the same pure sense of wonder he was born with, but he can shape something far more enduring and sustaining.''

(Incidentally, Kubrick doesn't explain how anything created by a person could expect to 'endure' or 'sustain' for longer than a few decades (a human memory), centuries (a statue, building or book) or millennia (a digitally archived version of this website, perhaps), but we'll let him off because 2001 was ace.)

The two ideas of the meaninglessness of our existence and the ephemeral nature of human happiness form the core of the 1932 novel Brave New World, 85 years old this year. Written in a style that is two parts cheerful extroversion and one part finger-wagging doom, this fairly ancient tome still gives all forward-thinking people the fear, and quite right too. It regularly makes the upper reaches of '100 Greatest Novels' lists as well, although whether most people appreciate it from the right angle is debatable.

This lack of comprehension is at least partly because it's so druggy, and easily dismissed as 'a drugs book' along the same lines as The Naked Lunch (William Burroughs, 1959) or Fear And Loathing In Las Vegas (Hunter S. Thompson, 1972). Its author, Aldous Huxley, might not have objected to this categorisation: he was a chap who enthusiastically explored the caverns of the mind, making his life's work an assiduous study of the spiritual plane and the substances you needed to get there.

Huxley's 1954 essay The Doors Of Perception is as well-known - and as frequently referenced by pop culturists - as Brave New World, and details his experience of a mescaline trip and subsequent musings on the fluid nature of reality. Famously, Huxley demonstrated his commitment to the cause by actually dying on acid, having asked his wife to inject him with a dose of LSD on his deathbed in 1963. It’s understandable, then, that he's occasionally categorised merely as a drug-snarfing drugs author who wrote druggy books about drugs.

In fact, Huxley's interest in subjective views of existence isn't central to the plot of Brave New World, a fuller work than The Doors Of Perception, but it definitely infuses the bigger questions behind its themes. It's really not just, or even largely, about drugs: the famous substance in the novel only symbolises the author's much more essential reflections on the human condition.

Here's a quick plot summary, spoilers included. The setting is a sterile World State in the year 2540 AF (After Ford, the car manufacturer). The world is at peace; all human needs are supplied; no-one lacks money or entertainment or comfort. Child-bearing has been eradicated, with batches of test-tube babies churned out by factories and conditioned in vitro to accept and enjoy their allotted social caste, from subliterate menial workers to a feckless elite. Intellectual rigour, religious devotion and philosophical thought are rare, with most citizens enjoying a careless, sensual existence based on freely-available sex and a ubiquitous drug called soma, distributed by the government. No-one is poor, fat, ugly or unhappy.

In this infantile utopia appear four misfits: Bernard Marx, an intelligent malcontent who is shunned because a rare genetic error has made him shorter than other men; Helmholtz Watson, a handsome intellectual who, like Bernard, is too clever for this perfect world; and a mother and son, Linda and John, who were accidentally abandoned outside civilisation and have lived without the benefit of education or age-defying medicine.

Brave New World sets these individuals against the power of the World State and watches them succumb, one by one. Bernard and Helmholtz are exiled; on returning to the World State to public revulsion at her ageing, overweight appearance, Linda gets permanently off her face on soma and then dies; John commits suicide, disgusted at the new world and his inability to stay free of its temptations. It's a clever, sad, horrible, funny book.

The novel's big themes are obviously still relevant. The idea of casual, consensual sex being freely available to all adults isn't controversial in the Tinder era, although it must have been fairly shocking to many readers in 1932. On the other hand, the theme of government-controlled genetic engineering on humans is still anathema to a lot of people, even outside the industrial and religious establishment. The public will come around to the idea sooner or later, though. The idea that a quick visit to a 'gene clinic' could prevent you and your kids from getting cancer is just too attractive.

Huxley's idea of people being pre-allocated before birth to a set station in life used to be a real social norm, but no more. Social mobility exists for most of us today, although - like Brave New World's characters - we're ruled by an unelected elite. In our case it's composed of corporate and military interests. If you don't grasp that, you're kidding yourself. The only difference is that the powers that be are not hidden: they're in plain view, and they feed us consumer durables instead of soma.

All this sociopolitical commentary by Huxley is easier to process than Brave New World's real question, though, which is: what does it mean to be happy?

''...there is always soma, delicious soma, half a gramme for a half-holiday, a gramme for a weekend, two grammes for a trip to the gorgeous East, three for a dark eternity on the moon...''

Familiar, isn’t it? A lot of us do exactly the same thing with various stimulants of choice every single weekend. Face it, if soma existed, you'd try it just to see what it was like. Yes, you would.

In Brave New World, soma is the only way for the masses to experience true happiness. The characters who try to achieve it any other way - through intellectual rigour, or in John’s case, via an antiquated Shakespearean moral code - end up excommunicated or dead. And worse, looking silly. John, a stranger to the self-indulgent World State, tries to live a 'moral' life by standards that are Old Testament in all but name. He whips himself cruelly, convinced that self-flagellation will make him 'better', and does the same to Lenina Crowne, a modern woman who he loves but whose casual promiscuity disgusts him. After being drawn into a soma-fuelled orgy, John kills himself, the author's punishment for his old-fashioned values. It's tragic but ridiculous.

Huxley is very skilful at all this. John's refusal to indulge in the World State's definition of happiness seems wholly unreasonable to the reader, thanks to Huxley's convincing view of what human needs are and how easily they can be satisfied. It's worrying how easily you find yourself seeing things from the World State's point of view.

For example, it seems entirely reasonable when the head of state - revealed as an affable, patriarchal 'Controller' called Mustapha Mond, not some Orwellian monster - tells John that in the modern world, life can be lived without inconveniences such as pain and fear.

''But I like the inconveniences.'' [said John].
'We don't,'' said the Controller. ''We prefer to do things comfortably.''
''But I don't want comfort. I want God, I want poetry, I want real danger, I want freedom, I want goodness. I want sin.''
''In fact,'' said Mustapha Mond, ''you're claiming the right to be unhappy.''
''All right then,'' said the Savage defiantly, 'I'm claiming the right to be unhappy.''
''Not to mention the right to grow old and ugly and impotent; the right to have syphilis and cancer; the right to have too little to eat; the right to be lousy; the right to live in constant apprehension of what may happen tomorrow; the right to catch typhoid; the right to be tortured by unspeakable pains of every kind.'' There was a long silence.
''I claim them all,'' said the Savage at last.
Mustapha Mond shrugged his shoulders. ''You're welcome,'' he said.

We’re not in the World State yet, clearly. There’s still way too much disease, poverty and general hatred for that. But we're moving in that direction, and Brave New World’s continued genius lies in predicting the collapse that will occur if we ever reach that point.

The book also asks us whether we’re equipped to cope with happiness levels beyond the fixed brain chemistry explained in Yuval Noah Harari's Sapiens and elsewhere. Do we know what that would feel like? Not without soma or its equivalent. We’re not at a point where our needs are perfectly met, and undoubtedly it will be better for us if we never quite get there.

The message, then and now, is that perfect happiness is not achievable, so don't strive to reach it. You're only human, after all, and there's a price for sentience. Now pass that bottle of claret.