...it won't just be the quality and quantity of consciousness in the world that will be transformed in the post-Darwinian Transition. As (post-)humanity emerges from the neurochemical Dark Ages, enriched dopaminergic function in particular may sharpen the sheer intensity and meaningfulness of every moment of conscious existence. For a generation whose lifetimes span both modes of awareness, it will be as if they had just woken up. They will feel they had hitherto been sleep-walking through life in a twilit stupor. Thereafter their former mundane and minimal existence may be recalled only as some kind of zombified trance-state whose nature they were physiologically incapable of recognising...

All moral tradeoffs are messy. However, on some fairly modest ethical assumptions, when a severe and irreconcilable conflict of interests occurs, then the interests of the more sentient take precedence over the less sentient. This rule of thumb holds regardless of the age, race or species of the victim.

As well as seriously – indeed exhaustively – researching everything that could conceivably go wrong, I think we should also investigate what could go right. The world is racked by suffering. The hedonic treadmill might more aptly be called a dolorous treadmill. Hundreds of millions of people are currently depressed, pain-ridden or both. Hundreds of billions of non-human animals are suffering too. If we weren't so inured to a world of pain and misery, then the biosphere would be reckoned in the throes of a global medical emergency. Thanks to breakthroughs in biotechnology, pain-thresholds, default anxiety levels, hedonic range and hedonic set-points are all now adjustable parameters in human and non-human animals alike. We are living in the final century of life on Earth in which suffering is biologically inevitable. As a society, we need an ethical debate about how much pain and misery we want to preserve and create.

True hedonic engineering, as distinct from mindless hedonism or reckless personal experimentation, can be profoundly good for our character. Character-building technologies can benefit utilitarians and non-utilitarians alike. Potentially, we can use a convergence of biotech, nanorobotics and information technology to gain control over our emotions and become better (post-)human beings, to cultivate the virtues, strength of character, decency, to become kinder, friendlier, more compassionate: to become the type of (post)human beings that we might aspire to be, but aren't, and biologically couldn't be, with the neural machinery of unenriched minds. Given our Darwinian biology, too many forms of admirable behaviour simply aren't rewarding enough for us to practise them consistently: our second-order desires to live better lives as better people are often feeble echoes of our baser passions.

In future, nerve cell responsiveness to naturally occurring endogenous opioids can be increased via receptor enrichment in the brain too. In principle, we can modulate their lifelong "overexpression", intermittently heightened (or gently diminished) by whatever kinds of personal and environmental contingencies we judge fit. Both functionally and anatomically, our reward pathways can be made "bigger and better". But intelligent emotional self-mastery will involve re-engineering the mind-brain so we derive the most intense rewards from activities we deem most lastingly worthwhile: i.e. prioritising our higher-order desires over legacy first-order appetites. Natural selection has "encephalised" our emotions to benefit our genes. Rational agents can "re-encephalise" our emotions to benefit us.

All that matters is the pleasure-pain axis. Pain and pleasure disclose the world's inbuilt metric of (dis)value. Our overriding ethical obligation is to minimise suffering. After we have reprogrammed the biosphere to wipe out experience below "hedonic zero", we should build a "triple S" civilisation based on gradients of superhuman bliss. The nature of ultimate reality baffles me. But intelligent moral agents will need to understand the multiverse if we are to grasp the nature and scope of our wider cosmological responsibilities. My working assumption is non-materialist physicalism. Formally, the world is completely described by the equation(s) of physics, presumably a relativistic analogue of the universal Schrödinger equation. Tentatively, I'm a wavefunction monist who believes we are patterns of qualia in a high-dimensional complex Hilbert space. Experience discloses the intrinsic nature of the physical: the "fire" in the equations. The solutions to the equations of QFT or its generalisation yield the values of qualia. What makes biological minds distinctive, in my view, isn't subjective experience per se, but rather non-psychotic binding. Phenomenal binding is what consciousness is evolutionarily "for". Without the superposition principle of QM, our minds wouldn't be able to simulate fitness-relevant patterns in the local environment. When awake, we are quantum minds running subjectively classical world-simulations. I am an inferential realist about perception. Metaphysically, I explore a zero ontology [...] the total information content of reality must be zero on pain of a miraculous creation of information ex nihilo. Epistemologically, I incline to a radical scepticism that would be sterile to articulate. Alas, the history of philosophy twinned with the principle of mediocrity suggests I burble as much nonsense as everyone else.

I think there's an asymmetry. There's this fable of Ursula Le Guin, short story, Ones Who Walk Away From Omelas. We're invited to imagine this city of delights, vast city of incredible wonderful pleasures but the existence of Omelas, this city of delights depends on the torment and abuse of a single child. The question is would you walk away from Omelas and what does walking away from Omelas entail. Now, personally I am someone who would walk away from Omelas. The world does not have an off switch, an off button and I think if one is whether a Buddhist of a negative utilitarian, or someone who believes in suffering-focused ethics, rather than to consider these theoretical apocalyptic scenarios it is more fruitful to work with secular and religious life lovers to phase out the biology of suffering in favor of gradients of intelligent wellbeing because one of the advantages of hedonic recalibration, i.e. ratcheting up hedonic set points is that it doesn't ask people to give up their existing values and preferences with complications.

Humans are prone to status quo bias. So let's do a thought-experiment. Imagine we stumble across an advanced civilisation that has abolished predation, disease, famine, and all the horrors of primitive Darwinian life. The descendants of archaic lifeforms flourish unmolested in their wildlife parks – free living, but not "wild". Should we urge scrapping their regime of compassionate stewardship of the living world – and a return to asphyxiation, disembowelling and being eaten alive? Or is a happy biosphere best conserved intact?

Today, status quo bias runs deep. Conservation biology is an ideology masquerading as a science. Many researchers seek to extend the tenets of conservation biology to humans. By contrast, a benevolent superintelligence might view Darwinian life on Earth as an infestation of biological malware and act accordingly. The amount of suffering caused by Homo sapiens is hard to quantify. But the suffering is immense and growing daily with the spread of industrialised animal abuse.

If we don't address the genetic causes of suffering (physical and mental) we will find ourselves in 500 years enjoying material abundance via nanotech, living in a perfect democracy, colonizing space, and still sitting around wondering "Why are we miserable so much of the time? Why can't we all just get along? Why are we not all happy?"