In everyday life we either express our beliefs in all-or-nothing terms or we resort to numerical probabilities: I believe it's going to rain or my chance of winning is one in a million. The Stability of Belief develops a theory of rational belief that allows us to reason with all-or-nothing belief and numerical belief simultaneously.

One of the fundamental problems of epistemology is to say when the evidence in an agent’s possession justifies the beliefs she holds. In this paper and its sequel, we defend the Bayesian solution to this problem by appealing to the following fundamental norm: Accuracy An epistemic agent ought to minimize the inaccuracy of her partial beliefs. In this paper, we make this norm mathematically precise in various ways. We describe three epistemic dilemmas that an agent might face if she attempts (...) to follow Accuracy, and we show that the only inaccuracy measures that do not give rise to such dilemmas are the quadratic inaccuracy measures. In the sequel, we derive the main tenets of Bayesianism from the relevant mathematical versions of Accuracy to which this characterization of the legitimate inaccuracy measures gives rise, but we also show that Jeffrey conditionalization has to be replaced by a different method of update in order for Accuracy to be satisfied. (shrink)

This monograph provides a new account of justified inference as a cognitive process. In contrast to the prevailing tradition in epistemology, the focus is on low-level inferences, i.e., those inferences that we are usually not consciously aware of and that we share with the cat nearby which infers that the bird which she sees picking grains from the dirt, is able to fly. Presumably, such inferences are not generated by explicit logical reasoning, but logical methods can be used to describe (...) and analyze such inferences. Part 1 gives a purely system-theoretic explication of belief and inference. Part 2 adds a reliabilist theory of justification for inference, with a qualitative notion of reliability being employed. Part 3 recalls and extends various systems of deductive and nonmonotonic logic and thereby explains the semantics of absolute and high reliability. In Part 4 it is proven that qualitative neural networks are able to draw justified deductive and nonmonotonic inferences on the basis of distributed representations. This is derived from a soundness/completeness theorem with regard to cognitive semantics of nonmonotonic reasoning. The appendix extends the theory both logically and ontologically, and relates it to A. Goldman's reliability account of justified belief. This text will be of interest to epistemologists and logicians, to all computer scientists who work on nonmonotonic reasoning and neural networks, and to cognitive scientists. (shrink)

In discussions about whether the Principle of the Identity of Indiscernibles is compatible with structuralist ontologies of mathematics, it is usually assumed that individual objects are subject to criteria of identity which somehow account for the identity of the individuals. Much of this debate concerns structures that admit of non-trivial automorphisms. We consider cases from graph theory that violate even weak formulations of PII. We argue that (i) the identity or difference of places in a structure is not to be (...) accounted for by anything other than the structure itself and that (ii) mathematical practice provides evidence for this view. We want to thank Leon Horsten, Jeff Ketland, Øystein Linnebo, John Mayberry, Richard Pettigrew, and Philip Welch for valuable comments on drafts of this paper. We are especially grateful to Fraser MacBride for correcting our interpretation of two of his papers and for other helpful comments. CiteULike Connotea Del.icio.us What's this? (shrink)

One of the fundamental problems of epistemology is to say when the evidence in an agent’s possession justifies the beliefs she holds. In this paper and its prequel, we defend the Bayesian solution to this problem by appealing to the following fundamental norm: Accuracy An epistemic agent ought to minimize the inaccuracy of her partial beliefs. In the prequel, we made this norm mathematically precise; in this paper, we derive its consequences. We show that the two core tenets of Bayesianism (...) follow from the norm, while the characteristic claim of the Objectivist Bayesian follows from the norm along with an extra assumption. Finally, we consider Richard Jeffrey’s proposed generalization of conditionalization. We show not only that his rule cannot be derived from the norm, unless the requirement of Rigidity is imposed from the start, but further that the norm reveals it to be illegitimate. We end by deriving an alternative updating rule for those cases in which Jeffrey’s is usually supposed to apply. (shrink)

We give an overview of the role of equicontinuity of sequences of real-valued functions on [0,1] and related notions in classical mathematics, intuitionistic mathematics, Bishop’s constructive mathematics, and Russian recursive mathematics. We then study the logical strength of theorems concerning these notions within the programme of Constructive Reverse Mathematics. It appears that many of these theorems, like a version of Ascoli’s Lemma, are equivalent to fan-theoretic principles.

This essay develops a joint theory of rational (all-or-nothing) belief and degrees of belief. The theory is based on three assumptions: the logical closure of rational belief; the axioms of probability for rational degrees of belief; and the so-called Lockean thesis, in which the concepts of rational belief and rational degree of belief figure simultaneously. In spite of what is commonly believed, this essay will show that this combination of principles is satisfiable (and indeed nontrivially so) and that the principles (...) are jointly satisfied if and only if rational belief is equivalent to the assignment of a stably high rational degree of belief. Although the logical closure of belief and the Lockean thesis are attractive postulates in themselves, initially this may seem like a formal “curiosity”; however, as will be argued in the rest of the essay, a very reasonable theory of rational belief can be built around these principles that is not ad hoc and that has various philosophical features that are plausible independently. In particular, this essay shows that the theory allows for a solution to the Lottery Paradox, and it has nice applications to formal epistemology. The price that is to be paid for this theory is a strong dependency of belief on the context, where a context involves both the agent's degree of belief function and the partitioning or individuation of the underlying possibilities. But as this essay argues, that price seems to be affordable. (shrink)

This article outlines what a formal theory of truth should be like, at least at first glance. As not all of the stated constraints can be satisfied at the same time, in view of notorious semantic paradoxes such as the Liar paradox, we consider the maximal consistent combinations of these desiderata and compare their relative advantages and disadvantages.

We present a way of classifying the logically possible ways out of Gärdenfors' inconsistency or triviality result on belief revision with conditionals. For one of these ways—conditionals which are not descriptive but which only have an inferential role as being given by the Ramsey test—we determine which of the assumptions in three different versions of Gärdenfors' theorem turn out to be false. This is done by constructing ranked models in which such Ramsey-test conditionals are evaluated and which are subject to (...) natural postulates on belief revision and acceptability sets for conditionals. Along the way we show that in contrast with what Gärdenfors himself proposed, there is no dichotomy of the form: either the Ramsey test has to be given up or the Preservation condition. Instead, both of them follow from our postulates. (shrink)

Recently, several scholars have argued that scientists can accept scientific claims in a collective process, and that the capacity of scientific groups to form joint acceptances is linked to a functional division of labor between the group members. However, these accounts reveal little about how the cognitive content of the jointly accepted claim is formed, and how group members depend on each other in this process. In this paper, I shall therefore argue that we need to link analyses of joint (...) acceptance with analyses of distributed cognition. To sketch how this can be done, I shall present a detailed case study, and on the basis of the case, analyze the process through which a group of scientists jointly accept a new scientific claim and at a later stage jointly accept to revise previously accepted claims. I shall argue that joint acceptance in science can be established in situations where an overall conceptual structure is jointly accepted by a group of scientists while detailed parts of it are distributed among group members with different areas of expertise, a condition that I shall call a heterogeneous conceptual consensus. Finally, I shall show how a heterogeneous conceptual consensus can work as a constraint against scientific change and address the question how changes may nevertheless occur. (shrink)

Gotthold Ephraim Lessing stands out among the thinkers of the 18th century for his refusal to synthesize theology and philosophy. But due to his notorious ambivalence about religious questions, even Lessing’s contemporaries remained uncertain whether he ultimately sided with the former or the latter. The short dialogue Hercules and Omphale is, to the detriment of research on this topic, largely unknown. I show that the dialogue offers in a nutshell Lessing’s comprehensive analysis of the intellectual and religious situation of his (...) time. By calling on the mythical travesty of the Asian queen and the Greek hero, Lessing illustrates the mutual attraction that has led astray both Enlightenment philosophy and contemporary Lutheran orthodoxy. Implicitly, his diagnosis of the aberrations of philosophy and theology sheds light on Lessing’s own position. The twofold criticism is an attempt to restore theology as well as philosophy in their genuine forms and to reestablish their proper relationship. Through his twofold restitutio in integrum, Lessing is able to reopen the quarrel between orthodoxy and the Enlightenment and, thus, to radically renew the all but forgotten theologico-philosophical antagonism. (shrink)

(No abstract is available for this citation).

Drawing on an idea proposed by Darwin, it has recently been hypothesised that violent intergroup conflict might have played a substantial role in the evolution of human cooperativeness and altruism. The central notion of this argument, dubbed ‘parochial altruism’, is that the two genetic or cultural traits, aggressiveness against out-groups and cooperativeness towards the in-group, including self-sacrificial altruistic behaviour, might have coevolved in humans. This review assesses the explanatory power of current theories of ‘parochial altruism’. After a brief synopsis of (...) the existing literature, two pitfalls in the interpretation of the most widely used models are discussed: potential direct benefits and high relatedness between group members implicitly induced by assumptions about conflict structure and frequency. Then, a number of simplifying assumptions made in the construction of these models are pointed out which currently limit their explanatory power. Next, relevant empirical evidence from several disciplines which could guide future theoretical extensions is reviewed. Finally, selected alternative accounts of evolutionary links between intergroup conflict and intragroup cooperation are briefly discussed which could be integrated with parochial altruism in the future. (shrink)

In interdisciplinary research scientists have to share and integrate knowledge between people and across disciplinary boundaries. An important issue for philosophy of science is to understand how scientists who work in these kinds of environments exchange knowledge and develop new concepts and theories across diverging fields. There is a substantial literature within social epistemology that discusses the social aspects of scientific knowledge, but so far few attempts have been made to apply these resources to the analysis of interdisciplinary science. Further, (...) much of the existing work either ignores the issue of differences in background knowledge, or it focuses explicitly on conflicting background knowledge. In this paper we provide an analysis of the interplay between epistemic dependence between individual experts with different areas of expertise. We analyze the cooperative activity they engage in when participating in interdisciplinary research in a group, and we compare our findings with those of other studies in interdisciplinary research. (shrink)

This is part A of a paper in which we defend a semantics for counterfactuals which is probabilistic in the sense that the truth condition for counterfactuals refers to a probability measure. Because of its probabilistic nature, it allows a counterfactual ‘ifAthenB’ to be true even in the presence of relevant ‘Aand notB’-worlds, as long such exceptions are not too widely spread. The semantics is made precise and studied in different versions which are related to each other by representation theorems. (...) Despite its probabilistic nature, we show that the semantics and the resulting system of logic may be regarded as a naturalistically vindicated variant of David Lewis’ truth-conditional semantics and logic of counterfactuals. At the same time, the semantics overlaps in various ways with the non-truth-conditional suppositional theory for conditionals that derives from Ernest Adams’ work. We argue that counterfactuals have two kinds of pragmatic meanings and come attached with two types of degrees of acceptability or belief, one being suppositional, the other one being truth based as determined by our probabilistic semantics; these degrees could not always coincide due to a new triviality result for counterfactuals, and they should not be identified in the light of their different interpretation and pragmatic purpose. However, for plain assertability the difference between them does not matter. Hence, if the suppositional theory of counterfactuals is formulated with sufficient care, our truth-conditional theory of counterfactuals is consistent with it. The results of our investigation are used to assess a claim considered by Hawthorne and Hájek, that is, the thesis that most ordinary counterfactuals are false. (shrink)

As recently stakeholders complain about the use of conflict minerals in consumer products that are often invisible to them in final products, firms across industries implement conflict mineral management practices. Conflict minerals are those, whose systemic exploitation and trade contribute to human right violations in the country of extraction and surrounding areas. Particularly, supply chain managers in the Western world are challenged taking reasonable steps to identify and prevent risks associated with these resources due to the globally dispersed nature of (...) supply chains and the opacity of the origin of commodities. Supply chain due diligence represents a holistic concept to proactively manage supply chains reducing the likelihood of the use of conflict minerals effectively. Based on an exploratory study with 27 semi-structured interviews within five European industries, we provide insights into patterns of implementation, key motivational factors, barriers and enablers, and impacts of SCDD in mineral supply chains. Our results contribute to both theory and practice as we provide first insights to SCDD practices and make recommendations for an industry-wide implementation of SCDD. Altogether, this study provides the basis for future theory testing research in the context of SCDD and conflict mineral management. (shrink)

Many discussions between realists and non-realists have centered on the issue of reference, especially whether there is referential stability during theory change. In this paper, I shall summarize the debate, sketching the problems that remain within the two opposing positions, and show that both have ended on their own slippery slope, sliding away from their original position toward that of their opponents. In the search for a viable intermediate position, I shall then suggest an account of reference which, to a (...) degree, follows the causal theory in explaining reference as carving the world at its joints. Contrary to the causal theory, however, I submit that this world is a phenomenal world whose variable joints exist only in a historical process in which they are transmitted gradually from one generation to the next. According to this account, the joints of the phenomenal world are constituted by family resemblance, where bundles of features that span bounded areas in perceptual space underlie the joints. Furthermore, the integrity of the cognitive process by which these joints are recognized depends on a transmission process by which new generations are presented with given joints and bundles by the preceding generation. Contrary to a traditional realist account, this heritage from the preceding generation may be transformed into new joints and bundles before transmission to new generations. This permits a continuous process of referential change in which the joints and bundles at different stages in the development of a theory can be connected by chains-of-reasoning. (shrink)

This is a review of David Löwenstein’s book "Know-how as Competence. A Rylean Responsibilist Account".

It has recently been proposed that the evolution of human cooperativeness might, at least in part, have started as the cooptation of behavioral strategies evolved for solving problems of coordination to solve problems with higher incentives to defect, i.e. problems of cooperation. Following this line of thought, we systematically tested human subjects for spillover effects from simple coordination tasks (2x2 Stag Hunt games, SH) to problems of cooperation (2x2 Prisoner’s Dilemma games, PD) in a laboratory experiment with rigorous controls to (...) rule out subject confusion or habituation. Supporting the hypothesis that decision mechanisms for cooperation problems are linked with decision mechanisms for coordination, our main finding is that cooperation levels in PD games embedded in a sequence of SH games were significantly increased compared to a baseline sequence consisting only of PDs when subjects played in fixed pairs. No such effects could be found when players were randomly rematched each round. Additional findings include that this spillover effect cannot prevent a decay of cooperation over time, that there is no indication of a reversed effect, i.e. no signs of negative spillovers from failed cooperation to miscoordination, and that subjects self-reported preferences in SH games are prosocial. (shrink)

When do children acquire a propositional attitude folk psychology or theory of mind? The orthodox answer to this central question of developmental ToM research had long been that around age 4 children begin to apply “belief” and other propositional attitude concepts. This orthodoxy has recently come under serious attack, though, from two sides: Scoffers complain that it over-estimates children’s early competence and claim that a proper understanding of propositional attitudes emerges only much later. Boosters criticize the orthodoxy for underestimating early (...) competence and claim that even infants ascribe beliefs. In this paper, the orthodoxy is defended on empirical grounds against these two kinds of attacks. On the basis of new evidence, not only can the two attacks safely be countered, but the orthodox claim can actually be strengthened, corroborated and refined: what emerges around age 4 is an explicit, unified, flexibly conceptual capacity to ascribe propositional attitudes. This unified conceptual capacity contrasts with the less sophisticated, less unified implicit forms of tracking simpler mental states present in ontogeny long before. This refined version of the orthodoxy can thus most plausibly be spelled out in some form of 2-systems-account of theory of mind. (shrink)

This article introduces, studies, and applies a new system of logic which is called ‘HYPE’. In HYPE, formulas are evaluated at states that may exhibit truth value gaps and truth value gluts. Simple and natural semantic rules for negation and the conditional operator are formulated based on an incompatibility relation and a partial fusion operation on states. The semantics is worked out in formal and philosophical detail, and a sound and complete axiomatization is provided both for the propositional and the (...) predicate logic of the system. The propositional logic of HYPE is shown to contain first-degree entailment, to have the Finite Model Property, to be decidable, to have the Disjunction Property, and to extend intuitionistic propositional logic conservatively when intuitionistic negation is defined appropriately by HYPE’s logical connectives. Furthermore, HYPE’s first-order logic is a conservative extension of intuitionistic logic with the Constant Domain Axiom, when intuitionistic negation is again defined appropriately. The system allows for simple model constructions and intuitive Euler-Venn-like diagrams, and its logical structure matches structures well-known from ordinary mathematics, such as from optimization theory, combinatorics, and graph theory. HYPE may also be used as a general logical framework in which different systems of logic can be studied, compared, and combined. In particular, HYPE is found to relate in interesting ways to classical logic and various systems of relevance and paraconsistent logic, many-valued logic, and truthmaker semantics. On the philosophical side, if used as a logic for theories of type-free truth, HYPE is shown to address semantic paradoxes such as the Liar Paradox by extending non-classical fixed-point interpretations of truth by a conditional as well-behaved as that of intuitionistic logic. Finally, HYPE may be used as a background system for modal operators that create hyperintensional contexts, though the details of this application need to be left to follow-up work. (shrink)

It is shown that a principle, which can be seen as a constructivised version of sequential compactness, is equivalent to a form of Brouwer’s fan theorem. The complexity of the latter depends on the geometry of the spaces involved in the former.

Thomas Kuhn's Structure of Scientific Revolutions became the most widely read book about science in the twentieth century. His terms 'paradigm' and 'scientific revolution' entered everyday speech, but they remain controversial. In the second half of the twentieth century, the new field of cognitive science combined empirical psychology, computer science, and neuroscience. In this book, the theories of concepts developed by cognitive scientists are used to evaluate and extend Kuhn's most influential ideas. Based on case studies of the Copernican revolution, (...) the discovery of nuclear fission, and an elaboration of Kuhn's famous 'ducks and geese' example of concept learning, this volume, first published in 2006, offers accounts of the nature of normal and revolutionary science, the function of anomalies, and the nature of incommensurability. (shrink)

This is a personal, incomplete, and very informal take on the role of logic in general philosophy of science, which is aimed at a broader audience. We defend and advertise the application of logical methods in philosophy of science, starting with the beginnings in the Vienna Circle and ending with some more recent logical developments.

Is it possible to give an explicit definition of belief in terms of subjective probability, such that believed propositions are guaranteed to have a sufficiently high probability, and yet it is neither the case that belief is stripped of any of its usual logical properties, nor is it the case that believed propositions are bound to have probability 1? We prove the answer is ‘yes’, and that given some plausible logical postulates on belief that involve a contextual “cautiousness” threshold, there (...) is but one way of determining the extension of the concept of belief that does the job. The qualitative concept of belief is not to be eliminated from scientific or philosophical discourse, rather, by reducing qualitative belief to assignments of resiliently high degrees of belief and a “cautiousness” threshold, qualitative and quantitative belief turn out to be governed by one unified theory that offers the prospects of a huge range of applications. Within that theory, logic and probability theory are not opposed to each other but go hand in hand. (shrink)

Pindar's victory songs teem with divinity. By exploring them within the lived religious landscapes of the fifth century BCE, Hanne Eisenfeld demonstrates that they are in fact engaged in theological work. Focusing on a set of mythical figures whose identities blur the boundaries between mortality and immortality, she newly interprets the value of immortality in the epinician corpus. Pindar's depiction of these figures responds to and shapes contemporary religious experience and revalues mortality as a prerequisite for the glory found (...) in victory. The book combines close reading and philological analysis with religious historical approaches to Pindar's songs and his world. It highlights the inextricability of Greek literature and Greek religion, and models a novel approach to Greek lyric poetry at the intersection of these fields. (shrink)

This book takes a distinctive and innovative approach to a relatively under-explored question, namely: Why do we have human rights? Much political discourse simply proceeds from the idea that humans have rights because they are human without seriously interrogating this notion. Egalitarian Rights Recognition offers an account of how human rights are created and how they may be seen to be legitimate: rights are created through social recognition. By combining readings of 19th Century English philosopher T.H. Green with 20th Century (...) political theorist Hannah Arendt, the author constructs a new theory of the social recognition of rights. He challenges both the standard ‘natural rights’ approach and also the main accounts of the social recognition of rights which tend to portray social recognition as settled norms or established ways of acting. In contrast, Hann puts forward a 10-point account of the dynamic and contingent social recognition of human rights, which emphasises the importance of meaningful socio-economic equality. (shrink)

In this chapter, we present supporting arguments for the claim that Order Ethics is a school of thought within ethics which is especially open to empirical evidence. With its focus on order frameworks, i.e., incentive structures, Order Ethical advice automatically raises questions on implementability, efficacy, and efficiency of such recommended institutions, all of which are empirical questions to a good extent. We illustrate our arguments by presenting a small selection of experiments from economics that we consider highly informative for Order (...) Ethics. These experiments vary in their details but share one common theme: individual decision-making and its aggregate results are tested against the background of incentive structures. In particular, these studies provide first insights on how unregulated markets influence moral behavior over time, how trial-and-error experiences convince subjects to migrate to more efficient institutions, and how default rules can influence fundamental choices of people. We argue that Order Ethics, for which implementability of any moral claim is an essential requirement, can largely benefit from the use of such experimental methods. Finally, we suggest the provision of self-commitment devices as one example of smart policy design that avoids paternalistic intrusions into individual liberty. (shrink)

How do human children come up to carve up and think of the world around them in its most general and abstract structure? And to which degree are these general forms of viewing the world shared by other animals, notably by non-human primates? In response to these questions of what could be called comparative metaphysics, this paper discusses new evidence from developmental and comparative research to argue for the following picture: human children and non-human primates share a basic framework of (...) natural ontology: they think about their natural surroundings in essentialist ways in terms of natural kind objects constituted by their essential properties, and in generic terms as governed by general descriptive regularities. In contrast, there is a great divide when it comes to how human children and non-human primates carve up their social environment: only human children then go on to use their essentialist and generic thinking for developing a distinctively social ontology, to conceive of their surrounding in terms of socially constituted objects governed by general prescriptive norms. (shrink)

This papers deals with the class of axiomatic theories of truth for semantically closed languages, where the theories do not allow for standard models; i.e., those theories cannot be interpreted as referring to the natural number codes of sentences only (for an overview of axiomatic theories of truth in general, see Halbach[6]). We are going to give new proofs for two well-known results in this area, and we also prove a new theorem on the nonstandardness of a certain theory of (...) truth. The results indicate that the proof strategies for all the theorems on the nonstandardness of such theories are "essentially" of the same kind of structure. (shrink)

We show that a set of prima facie plausible assumptions on the relation of meaning resemblance – one of which is a compositionality postulate – is inconsistent. On this basis we argue that either there is no theoretically useful notion of semantic resemblance at all, or the traditional conception of the compositionality of meaning has to be adapted. In the former case, arguments put forward by Nelson Goodman and Paul Churchland in favor of the concept of meaning resemblance are defeated. (...) In the other case, it must be possible to account for 'degrees of compositionality' or for other refinements of compositionality that are compatible with meaning resemblance. (shrink)

Abstract: Focusing on early child pretend play from the perspective of developmental psychology, this article puts forward and presents evidence for two claims. First, such play constitutes an area of remarkable individual intentionality of second-order intentionality (or 'theory of mind'): in pretence with others, young children grasp the basic intentional structure of pretending as a non-serious fictional form of action. Second, early social pretend play embodies shared or collective we-intentionality. Pretending with others is one of the ontogenetically primary instances of (...) truly cooperative actions. And it is a, perhaps the, primordial form of cooperative action with rudimentary rule-governed, institutional structure: in joint pretence games, children are aware that objects collectively get assigned fictional status, 'count as' something, and that this creates a normative space of warranted moves in the game. Developmentally, pretend play might even be a cradle for institutional phenomena more generally. (shrink)

Brain Organoids in their current state of development are patentable. Future brain organoids may face some challenges in this regard, which I address in this contribution. Brain organoids unproblematically fulfil the general prerequisites of patentability set forth in Art. 3 (1) EU-Directive 98/44/ec (invention, novelty, inventive step and susceptibility of industrial application). Patentability is excluded if an invention makes use of human embryos or constitutes a stage of the human body in the individual phases of its formation and development. Both (...) do not apply to brain organoids, unless ES-cells are used. Art. 6 (1) EU-Directive 98/44/ec excludes patentability for inventions “the commercial exploitation of which would be contrary to ordre public or morality”. While there is no conceivable scenario, in which the commercial application of current brain organoids violates the ordre public, the same is not necessarily true for future brain organoids. Keeping in mind that a development of consciousness-like abilities in future brain organoids cannot be excluded and that an ability for both physical and psychological suffering has been theorized, both of which are aspects of the ordre public, certain applications of future brain organoids may constitute a violation of the ordre public and therefore lead to an exclusion of patentability. (shrink)

Several investigations have shown language impairments following electrode implantation surgery for Deep Brain Stimulation (DBS) in movement disorders. The impact of the actual stimulation, however, differs between DBS targets with further deterioration in formal language tests induced by thalamic DBS in contrast to subtle improvement observed in subthalamic DBS. Here, we studied speech samples from interviews with participants treated with DBS of the thalamic ventral intermediate nucleus (VIM) for essential tremor (ET), or the subthalamic nucleus (STN) for Parkinson’s disease (PD), (...) and healthy volunteers (eachn= 13). We analyzed word frequency and the use of open and closed class words. Active DBS increased word frequency in case of VIM, but not STN stimulation. Further, relative to controls, both DBS groups produced fewer open class words. Whereas VIM DBS further decreased the proportion of open class words, it was increased by STN DBS. Thus, VIM DBS favors the use of relatively common words in spontaneous language, compatible with the idea of lexical simplification under thalamic stimulation. The absence or even partial reversal of these effects in patients receiving STN DBS is of interest with respect to biolinguistic concepts suggesting dichotomous thalamic vs. basal ganglia roles in language processing. (shrink)