The Middle English term ‘jest’, derived from the Old French ‘geste’, referred either to heroic deeds such as those narrated in the medieval chansons de geste or to the narratives themselves. Only in the Renaissance did ‘jest’ accrue the connotations of humour. A close look at Shakespeare’s plays reveals a plethora of instances where ‘jest’ bears the connotations of make-believe - notably in Hamlet’s mocking remark that the Players ‘do but jest, poison in jest’ (Ham. iii.ii.17). In comedies such as The Taming of the Shrew, Twelfth Night, and The Merry Wives of Windsor, the term ‘jest’ is identified with the metadramatic insets in the plays. I argue that Shakespeare’s catachrestic use of ‘jest’ does not only glance at the Augustinian definition of jokes as fictions, but serves the purpose of exploring the divide between the serious and the playful, reality and make-believe, querying to what extent our realities too are grounded in illusions.

Most Greek thinkers regarded subjective states as modes of accessing objective reality. However, some challenged this realist stance in different ways. The chapter discusses philosophers and theories that belong to the latter group, insofar as they can be claimed to develop different conceptions of subjectivity and, correspondingly, subjectivist – that is, mind-dependent – accounts of the world, knowledge, and the good. The discussion begins with Protagoras’ “man-measure” doctrine, assessing whether it entails epistemic or axiological relativism. It then considers Plato’s Theaetetus and the so-called secret doctrine of flux, which grounds the thesis that knowledge is perception in a radical account of perceptual relativity. The Cyrenaics are examined as proponents of a more explicitly subjectivist epistemology, emphasizing the incorrigibility and privacy of pathē. Finally, the atomist theory of Democritus is explored, focusing on his account of sensible qualities, and the relation between perception and reality. Together, these case studies reveal the diversity of ancient approaches to subjectivism, ranging from mild relativism to proto-Cartesian emphases on the privacy of experience.

Perceptual Modal Collapse is the view that no unperceived perceptibles exist. Aristotle takes Perceptual Modal Collapse to be central to Protagoreanism. But Aristotle’s Categories 7 commits Aristotle to Perceptual Modal Collapse: perception and perceptible correlate; each relative pair is constituted by its relation to its correlative; correlatives exist at all the same times; so, perception and perceptible exist at all the same times. Hence, there are no unperceived perceptibles. Moreover, correlatives are simultaneous by nature. Aristotle’s arguments that this does not apply to perception and perceptible are unconvincing. I argue that Aristotle’s second definition of relatives can save Aristotle’s theory from Perceptual Modal Collapse, since the definition distinguishes perceptible as a schematic relative from specific perceptible qualities. Once we disambiguate, we can see that specific perceptibles need not exist at the same time as perceptions. Thus, the specific heat of a fire in a forest can exist, even when unperceived. These ideas underlie Aristotle’s account of intentional relatives in Metaphysics 5.15, where specific perceptual qualities are the content of perceptions.

In what respects can Epicurean philosophers be described as relativists? After an initial survey, this chapter focuses on their defence of the view that all sense-perceptions are true. Other philosophers associated with this thesis, such as Protagoras, are often taken to be committed to some form of relativism. At first glance, the Epicurean position appears to be quite different: they provide accounts of the mechanics of perception that purport to show that the reports provided by the senses are invariably faithful to some aspect of objective reality. But Plutarch alleges that Epicurus and his followers are in fact relativists in this context. I investigate this claim and argue that this is to some extent a fair characterisation—on the Epicurean account, many perceptual properties do turn out to be relative, in that an object that possesses such a property does so only in relation to some perceiving agent (and may lack it in relation to other agents at that time, or that agent at other times). But other perceptual properties are taken to be non-relative, and on the Epicurean view, sense perceptions are all true tout court, rather than merely in relation to some relevant agent.

In Chapter 3, human consciousness is discussed, including the need for legal recognition of the capacity of humans to communicate, emote, and perceive. The impact of technology on consciousness and human bonding is noted, such as generative AI that may reduce human literacy and the capacity to communicate.

Since the 1972 Stockholm Conference, many global environmental agreements have been struck for climate, biodiversity, and sustainable development goals. Still, the planets environment has continued to decline, including on the ocean. One result has been ocean acidification, caused by the uptake of 30–40 per cent of all carbon dioxide from the atmosphere. On its face, this ocean CO2 uptake sounds positive. However, with a continuous increase of CO2 in the atmosphere, this also means an increase in the ocean, which alters its chemistry in ways that may disrupt oceanic biodiversity through making waters more acidic. When coupling this with other major global crisis, we see that we have only adopted global environmental agreements that protect humans from our own nature-induced change – and not ensured that we take our ethical obligation to nature itself by protecting it from human use. This chapter looks at the risk perception literature and considers how the science–policy interface can be exploited to convey the importance of ocean acidification, and whether the anthropogenic lens is what will always be necessary to ensure action to protect something from ourselves.

The problem of perception – how far we can trust the senses, and how we come to believe what we think we know about the external world – goes back to the ancient Greeks. Naive realism – that we immediately know reality in what we see – is refuted by cases in which appearances are obviously distorted by perceptual artifacts, like the black drop in the case of transits of Venus. Perhaps the most famous case of the difficulty in visual telescopic observations is that of the canals of Mars, which led to a long-running controversy, not only among observers but engaging the wider public as well, about the nature of the actual surface markings of the red planet. In the end, there proved to be no canals in the artifactual sense, and instead the subtleties of perception revealed themselves – which include the nature of the visual system, the way that sense-information is processed in the brain, and the way the brain uses guided perception and prediction to make “sense” of the sense perceptions.

Every serious analyst of Britain’s role in global politics understood that the country’s decision to leave the European Union would have a significant – perhaps fundamental – effect on its standing in the wider world and the way it would henceforth pursue its foreign, defence and security policies. It was the biggest strategic reorientation in Britain’s external relations for over half a century; a shift for which the country was completely unprepared and in which the policy establishment was explicitly prevented from doing any contingency planning. With the shock of the Brexit decision in 2016, the prospects for British foreign affairs seemed to range from the excitingly uncertain to the simply dire. In the event, Britain’s standing in the world has both risen and sunk in the decade since, driven by challenges, events and responses only peripherally connected to Brexit issues as they arose at the time. ‘Brexit Britain’ certainly figures in the way the country is perceived internationally, but those perceptions are overlaid by more imperative judgements about how the country now positions itself in response to more fundamental challenges than were ever envisaged in Brexit debates at the time.

We are living through a period of growing global disorder. There are various causes, but one is the declining unity and efficacy of the political ‘West’ – the coalition of countries, including the UK and led by the United States, that came together after the Second World War to defend and promote liberal democracy at home and open markets abroad. For countries like ours, in a changed and changing geopolitical landscape, the challenge is not to build a single new world order, but instead to contribute to what the historian Adam Tooze calls ‘world ordering’. This means coalitions of the willing, on a range of issues, to meet the challenges that people and nations need to face together. This imperative makes Britain’s relationship with other European countries, and the EU, more important, not less. These countries, and the EU, have shared values and interests with the UK. We face a common threat from an increasingly anarchic form of ‘might makes right’ globalisation. So we need to renew our cooperation that was sabotaged by Brexit.

This chapter explores human cognition as a set of interconnected processes – perception, memory, attention, learning, reasoning, and executive function that allow us to adapt flexibly to complex environments. It contrasts human cognition with artificial intelligence, showing how neural networks and transformers borrow inspiration from the brain but lack intuition, context sensitivity, and self-awareness. Through examples from neuroscience and AI, the chapter highlights how both systems process information, learn, and make decisions. It argues that the future lies not in replacing human cognition but in building augmented cognition – partnerships where AI amplifies human thought and creativity rather than substituting for it.

The biggest problem that the vote threw up was precisely the lack of clarity about what would come next; what unexpected surprises were to come next? What would the UK’s departure mean for Britain and for the European Union; what, indeed, would it mean for countries in other parts of the world? Would Brexit start a domino effect in Europe; might it even start a chain reaction elsewhere too, as countries stepped back from international commitments and out of regional or global institutions – and turned their backs on former partners and allies? In the days after the vote, press commentaries around the world began to harden. On 24 June 2016, for example, the Chinese Ministry of Foreign Affairs noted that it respected the results and hoped for early agreements between London and Brussels to help clear up uncertainty. Three weeks later, voices in Beijing had a better grasp on what had happened – and in particular realised that the promises given by Brexit’s chief cheerleaders were hopelessly naïve at best and downright dissimulations at worst.