GWF Hegel (1770-1831) wanted to construct nothing less than a complete explanation of reality - nature, consciousness, art, history, politics, the lot - based on a single self-explanatory idea. Whether or not he succeeded is an interesting question (spoiler: he didn't), but more interesting is the question of why philosophy has become so much less ambitious since then, and what we can learn from Hegel today.

Philosophers have traditionally thought of grief as something that attaches to immediate loss - the death of a loved one, something terrible that's happened to us personally. But as the environmental crisis continues to wreak havoc on human and non-human lives, the philosophy of emotions needs a concept that captures a response to loss that perhaps hasn't happened yet, or loss that affects other people we may never meet: eco-grief.

There's something about space that's always captured the human imagination, but what happens when space begins to capture the imagination of billionaire tech entrepreneurs? In the past, we've visited space for scientific purposes, but now the grand vision is colonisation, permanent human settlement on the Moon, Mars and even further afield, with such ventures along the way as asteroid mining, which promises to deliver untold riches. The technical challenges are immense - as are the ethical ones.

Commercial surrogacy - the practice of paying someone to gestate your child and then hand it over when it's born - is banned in Australia, but it has its supporters. Defenders of commercial surrogacy argue that it should be legal for someone to receive payment for the labour of carrying a child, on the grounds that surrogacy constitutes a legitimate form of work. But are there some things that just shouldn't be for sale? This week we're testing the arguments.

The traditional philosophical view of belief is that it's a rational cognitive affair, evidence based and directed toward truth. According to this account, things like delusion and religious belief are "edge cases", exceptions that prove the rule. But this week we're considering not only that belief may be closely tied to emotion, but that it may actually be a form of emotion itself.

Collins Dictionary made "permacrisis" their word of the year in 2022 - a prescient choice because since then, the crises have just kept coming. Permacrisis is forcing us to take a close look at the way we communicate, because while free public discourse is one of the cornerstones of democracy, there's something about the nature of today's public discourse that fuels crisis, and keeps us frozen in a fight-or-flight posture.

Elite sport is traditionally a celebration of the human, but for how much longer? We watch in awe as athletes perform feats of skill, strength and endurance,  and experience the high drama of triumph and defeat -  but it's all on a human scale, or at least it has been until now. Sport and technology have always been intertwined, but with the advent of AI, this week we're wondering if the human element of sport - the physical dimension, but also the ethical - might be under threat.

Why are we so repelled yet fascinated by bodily waste? Today we're talking purity, pollution, colonial sanitation regimes, medicine and public health, and how they've been shaped by our deeply ambivalent attitudes to the stuff we all produce (ideally) every day, but rarely think about deeply.

There's a certain kind of question that raises suspicion as to the motives of the person asking it. 'Was the Holocaust really as bad as historians have made out?' 'Is there really a scientific consensus on climate change?' 'How do we now for sure that vaccines aren't harmful?' These kinds of questions can be read on the surface as innocent enquiry, but sometimes they can function as a kind of epistemic sabotage, casting doubt on settled issues and seeking to undermine confidence in established truth. How can we tell the difference between sincerity and bad faith? And how should we respond to the latter?

To call the effects of a fire, flood or cyclone these days a 'natural' disaster only tells part of the story, as climate change makes us realise that vulnerability to harm is often the result of factors that actually have little to do with weather events. Land theft, displacement, poverty and the legacies of colonial rule can all multiply climate harms, which means that climate justice is more than simply a matter of sustainable energy development or transitioning to a greener economy.