What is curiosity? An attractive option is that it is a desire to know. This analysis has been recently challenged by what I call interrogativism, the view that inquiring attitudes such as curiosity have questions rather than propositions as contents. In this paper, I defend the desire-to-know view, and make three contributions to the debate. First, I refine the view in a way that avoids the problems of its simplest version. Second, I present a new argument for the desire-to-know view that focuses on ascriptions of the form ‘S is curious to ϕ’, which, despite their prevalence, have been ignored in the literature. Third, I examine the central motivation for interrogativism – the argument from metacognition, according to which animals can be curious yet do not have the metacognitive capacities required by desires to know – and argue that it rests on questionable assumptions about desires and attitude ascriptions.

Recent debates on the nature of preferences in economics have typically assumed that they are to be interpreted either as behavioural regularities or as mental states. In this paper I challenge this dichotomy and argue that neither interpretation is consistent with scientific practice in choice theory and behavioural economics. Preferences are belief-dependent dispositions with a multiply realizable causal basis, which explains why economists are reluctant to make a commitment about their interpretation.

Philosophers often talk about and engage with ideas. Scientists, artists, and historians do, too. But what is an idea? In this paper, we first motivate the desire for an ontology of ideas before discussing what conditions a candidate ontology would have to satisfy to be minimally adequate. We then offer our own account of the ontology of ideas and consider various strategies for specifying the underlying metaphysics of the account. We conclude with a discussion of potential future work to be done on the ontology of ideas.

In economics, three nested organizational levels, namely behavioural, mental and neural, can be distinguished. They introduce specific theoretical or observable concepts and suggest their own models for choice making. If psycho-economics relates implemented actions to declared mental states, neuro-economics relates mental states to brain areas. Bridge principles can be defined which link concepts with similar interpretations at two successive levels. Thanks to these principles, relations or even models independently suggested at two successive levels may well be associated. Some prescriptive applications of these principles were more recently proposed, but they remain grounded on a too fragile basis.

Most people who are regular consumers of psychoactive drugs are not drug addicts, nor will they ever become addicts. In neurobiological theories, non-addictive drug consumption is acknowledged only as a “necessary” prerequisite for addiction, but not as a stable and widespread behavior in its own right. This target article proposes a new neurobiological framework theory for non-addictive psychoactive drug consumption, introducing the concept of “drug instrumentalization.” Psychoactive drugs are consumed for their effects on mental states. Humans are able to learn that mental states can be changed on purpose by drugs, in order to facilitate other, non-drug-related behaviors. We discuss specific “instrumentalization goals” and outline neurobiological mechanisms of how major classes of psychoactive drugs change mental states and serve non-drug-related behaviors. We argue that drug instrumentalization behavior may provide a functional adaptation to modern environments based on a historical selection for learning mechanisms that allow the dynamic modification of consummatory behavior. It is assumed that in order to effectively instrumentalize psychoactive drugs, the establishment of and retrieval from a drug memory is required. Here, we propose a new classification of different drug memory subtypes and discuss how they interact during drug instrumentalization learning and retrieval. Understanding the everyday utility and the learning mechanisms of non-addictive psychotropic drug use may help to prevent abuse and the transition to drug addiction in the future.

Our book examines the mechanisms that underlie social behavior and communication in East African vervet monkeys. Our goal is to describe the sophistication of primate intelligence and to probe its limits. We suggest that vervets and other primates make good primatologists. They observe social interactions, recognize the relations that exist among others, and classify relationships into types. Monkeys also use sounds to represent features of their environment and compare different vocalizations according to their meaning. Monkeys may use abstract concepts and have motives, beliefs, and desires, however, their mental states are apparently not accessible: They do not know what they know. In addition, monkeys seem unable to attribute mental states to others: They lack a “theory of mind.” Their inability to. examine their own mental states or to attribute mental states to others severely constrains their ability to transmit information or to deceive one another. It also limits the extent to which their vocalizations can be called semantic. Finally, the skills that monkeys exhibit in social behavior are apparently domain specific. For reasons that are at present unclear, vervets exhibit adaptive specializations in social interactions that are not extended to their interactions with other species (although they should be).

To study animal welfare empirically we need an objective basis for deciding when an animal is suffering. Suffering includes a wide range ofunpleasant emotional states such as fear, boredom, pain, and hunger. Suffering has evolved as a mechanism for avoiding sources ofdanger and threats to fitness. Captive animals often suffer in situations in which they are prevented from doing something that they are highly motivated to do. The “price” an animal is prepared to pay to attain or to escape a situation is an index ofhow the animal “feels” about that situation. Withholding conditions or commodities for which an animal shows “inelastic demand” (i.e., for which it continues to work despite increasing costs) is very likely to cause suffering. In designing environments for animals in zoos, farms, and laboratories, priority should be given to features for which animals show inelastic demand. The care ofanimals can thereby be based on an objective, animal-centered assessment of their needs.

The intentional stance is the strategy of prediction and explanation that attributes beliefs, desires, and other “intentional” states to systems – living and nonliving – and predicts future behavior from what it would be rational for an agent to do, given those beliefs and desires. Any system whose performance can be thus predicted and explained is an intentional system, whatever its innards. The strategy of treating parts of the world as intentional systems is the foundation of “folk psychology,” but is also exploited (and is virtually unavoidable) in artificial intelligence and cognitive science more generally, as well as in evolutionary theory. An analysis of the role of the intentional stance and its presuppositions supports a naturalistic theory of mental states and events, their content or intentionality, and the relation between “mentalistic” levels of explanation and neurophysiological or mechanistic levels of explanation. As such, the analysis of the intentional stance grounds a theory of the mind and its relation to the body.