Introduction

This chapter introduces the reader to the main purpose of the volume which is to provide a comprehensive survey of live debates about the philosophy of contract law and the role that they play in understanding fundamental contractual principles and the rules and doctrines that animate this area of law. Rather than summarise all of the contributions to the volume, the chapter picks out three recurrent themes: first, the growing trend toward pluralistic rather than monistic accounts of contract law, such as the dominant promise theory, which might suggest a renewed emphasis on explaining contract doctrine and a ‘political turn’ in the literature; second, the nature of the fundamental principle of freedom of contract and its limits located in purposes internal or external to contract; and, finally, how contract theory struggles with hard cases of rules and doctrines that seem to diverge from the requirements of interpersonal morality, such as the law on third parties and the handling of contractual debt claims. Bridging the gap between theory and practice here suggests links between the problem of hard cases, the trend toward pluralism, and the interaction between internal and external values to explain contract doctrine

A systematic review of modelling methods for studying the integration of hydrogen into energy systems

Hydrogen could be generated, stored, transported, and consumed in various ways, making it a promising solution to carbon emission reduction. However, key questions still remain in how hydrogen could be appropriately integrated into energy systems over time while coupling with different sectors. This has led to model-based studies of the whole system value of hydrogen in future energy systems, and the near-term actions and long-term strategies required to facilitate the transition to low-carbon energy systems with hydrogen. In this paper, a systematic review of the existing model-based studies in this area was conducted. A summary of hydrogen applications in energy systems was made, with statistics of publications and projects revealing the fast-growing interest in hydrogen in the past several years. The modelling methods used to investigate the system integration of hydrogen was summarised from over 130 publications. This paper also identified the gaps in modelling capability and potential future research topics: 1) balance between the resolution and modelling complexity, 2) inclusion of all uncertain factors of hydrogen pathways, 3) advancement of modelling approaches to address the chicken-and-egg dilemma of hydrogen economy development, and 4) a more detailed and comprehensive coverage of various interactions between hydrogen and other sectors

Expectations about presence enhance the influence of content-specific expectations on low-level orientation judgements

Will something appear and if so, what will it be? Perceptual expectations can concern both the presence and content of a stimulus. However, it is unclear how these different types of expectations interact with each other in biasing perception. Here, we tested how expectations about stimulus presence and content differently affect perceptual inference. Across separate online discovery (N = 110) and replication samples (N = 218), participants were asked to judge both the presence and content (orientation) of noisy grating stimuli. Crucially, preceding compound cues simultaneously and orthogonally predicted both whether a grating was likely to appear as well as what its orientation would be. Across both samples we found that content cues affected both discrimination and presence judgements directly, namely by biasing the orientation judgements in the expected direction and enhancing confidence in stimulus presence on congruent trials. In contrast, presence cues did not affect discrimination judgements directly. Instead, presence cues influenced discrimination judgements indirectly by enhancing the effect of the orientation cues when expecting a stimulus to be present. This was the case on trials where a stimulus was present, as well as on grating-absent trials. Further, presence cues directly affected confidence in stimulus presence. This suggests that presence expectations may act as a regulatory volume knob for the influence of content expectations. Further, modelling revealed higher sensitivity in distinguishing between grating presence and absence following absence cues than presence cues, demonstrating an asymmetry between gathering evidence in favour of stimulus presence and absence. Finally, evidence for overweighted expectations being associated with hallucination-like perception was inconclusive. In sum, our results provide nuance to popular predictive processing accounts of perception by showing that expectations of presence and content have distinct but interacting roles in shaping conscious perception