Popper’s (1983, 2002) philosophy of science has enjoyed something of a renaissance in the wake of the replication crisis, offering a philosophical basis for the ensuing science reform movement. However, adherence to Popper’s approach may also be at least partly responsible for the sense of “crisis” that has developed following multiple unexpected replication failures. In this article, I contrast Popper’s approach with that of Lakatos (1978) as well as with a related but problematic approach called naïve methodological falsificationism (NMF; Lakatos, 1978). The Popperian approach is powerful because it is based on logical refutations, but its theories are noncausal and, therefore, potentially lacking in scientific value. In contrast, the Lakatosian approach considers causal theories, but it concedes that these theories are not logically refutable. Finally, NMF represents a hybrid approach that subjects Lakatosian causal theories to Popperian logical refutations. However, its tactic of temporarily accepting a ceteris paribus clause during theory testing may be viewed as scientifically inappropriate, epistemically inconsistent, and “completely redundant” (Lakatos, 1978, p. 40). I conclude that the replication “crisis” makes the most sense in the context of the Popperian and NMF approaches because it is only in these two approaches that the failure to replicate a previously corroborated theory represents a logical refutation of that theory. In contrast, such replication failures are less problematic in the Lakatosian approach because they do not logically refute theories. Indeed, in the Lakatosian approach, replication failures can be temporarily ignored or used to motivate theory development.

Despite its being one of Roger Penrose’s greatest contributions to spacetime physics, there is a dearth of philosophical literature on twistor theory. The one exception to this is Bain (2006)—but although excellent, there remains much to be said on the foundations and philosophy of twistor theory. In this article, we (a) present for philosophers an introduction to twistor theory, (b) consider how the spacetime–twistor correspondence interacts with the philosophical literature on theoretical equivalence, and (c) explore the bearing which twistor theory might have on philosophical issues such as the status of dynamics, the geometrisation of physics, spacetime ontology, the emergence of spacetime, and symmetry-to-reality inferences. We close with an elaboration of a variety of further opportunities for philosophical investigation into twistor theory.

A growing number of linguistic attempts to explain how languages change use cultural-evolutionary models involving selection or drift. Developmental constraints and biases, which take center stage in evolutionary developmental biology or evo-devo, seem to be absent within this framework, even though linguistics is home to numerous notions of constraint. In this paper, we show how these evo-devo concepts could be applied to linguistic change and why they should. This requires some conceptual groundwork, due to important differences between linguistic and biotic evolution. In biological evolution, development generates the organism's variable traits on which selection and drift act. In linguistic evolution by analogy, we say development generates the linguistic variants on which selection and drift can act. “Linguistic development” then picks out how individual speakers produce and comprehend language. It involves much more than just learning. Using this broad notion of development, we distinguish between different types of bias that could operate in the processes of linguistic innovation and transmission, which correspond to genetic mutation and biological reproduction, respectively. Having thus sharpened our conceptual toolbox, we then reanalyze two well-documented cases of linguistic change and show that, in both these cases, linguists have only considered Neo-Darwinian evolutionary explanations, falsely deploying an exclusive disjunction of selection and drift. We show that there is at least a third relevant alternative in these examples, namely developmental constraint or bias in the sense we explicate here.

We provide a quantitative analysis of the philosophy-neuroscience nexus using citation analysis. Combining bibliometric indicators of cross-field visibility with journal citation mapping techniques, we investigate four dimensions of the nexus: how the visibility of neuroscience in philosophy and of philosophy in neuroscience has changed over time, which areas of philosophy are more interested in neuroscience, which areas of neuroscience are more interested in philosophy, and how the trading zone between the two fields is configured. We also discuss two hypotheses: the supposed occurrence of a neuro-revolution in philosophy and the role of psychology as the disciplinary link between neuroscience and philosophy. Both the visibility of neuroscience in philosophy and the visibility of philosophy in neuroscience have increased significantly from 1980 to 2020, albeit the latter remains an order of magnitude lower than the former. Neuroscience is particularly visible in philosophy of mind, applied ethics, philosophy of science, but not in ‘core’ areas of analytic philosophy. Philosophy is particularly visible in cognitive and systems neuroscience and neuropsychiatry, but not in biomedical neuroscience. As for the trading zone between philosophy and neuroscience, our data show that it works differently in philosophy and in neuroscience. While some philosophy journals are active loci of bidirectional communication, neuroscience journals are divided between journals ‘importing’ philosophy in neuroscience and journals ‘exporting’ neuroscience to philosophy. Lastly, data do not support the hypothesis that a widespread neuro-revolution has transformed philosophy radically, but support the hypothesis that psychology functions as a mediating disciplinary link between philosophy and neuroscience.

Scientific realists don’t standardly discriminate between, say, biology and fundamental physics when deciding whether the evidence and explanatory power warrant the inclusion of new entities in our ontology. As such, scientific realists are committed to a lush rainforest of special science kinds (Ross, 2000). Viruses certainly inhabit this rainforest – their explanatory power is overwhelming – but viruses’ properties can be explained from the bottom up: reductive explanations involving amino acids are generally available. However, reduction has often been taken to lead to a metaphysical downgrading, so how can viruses keep their place in the rainforest? In this paper, we show how the inhabitants of the rainforest can be inoculated against the eliminative threat of reduction: by demonstrating that they are emergent. According to our account, emergence involves a screening off condition as well as novelty. We go on to demonstrate that this account of emergence, which is compatible with theoretical reducibility, satisfies common intuitions concerning what should and shouldn’t count as real: viruses are emergent, as are trout and turkeys, but philosophically gerrymandered objects like trout-turkeys do not qualify.