I examine different arguments that could be used to establish indeterminism of neurological processes. Even though scenarios where single events at the molecular level make the difference in the outcome of such processes are realistic, this falls short of establishing indeterminism, because it is not clear that these molecular events are subject to quantum mechanical uncertainty. Furthermore, attempts to argue for indeterminism autonomously (i.e., independently of quantum mechanics) fail, because both deterministic and indeterministic models can account for the empirically observed behavior of ion channels.

There is a need to bring the work of philosophers such as Millikan who take an evolutionary approach to the study of the mind more in harmony with work in the cognitive neurosciences. Studies of the brain suggest that knowledge in the cortex may be organized by sensory modality-specific properties rather than by hierarchies of substance concepts, regardless of how adaptive Millikan argues the latter would be. Ryder's work on SINBAD networks, which purports to support Millikan's conclusions, does not decide this issue. The ability to make cross-modal identifications of individuals and kinds may be only a recent evolutionary adaptation.

The study of similarity is fundamental to biological inquiry. Many homology concepts have been formulated that function successfully to explain similarity in their native domains, but fail to provide an overarching account applicable to variably interconnected and independent areas of biological research despite the monistic standpoint from which they originate. The use of multiple, explicitly articulated homology concepts, applicable at different levels of the biological hierarchy, allows a more thorough investigation of the nature of biological similarity. Responsible epistemological pluralism as advocated herein is generative of fruitful and innovative biological research, and is appropriate given the metaphysical pluralism that underpins all of biology.

The method in human genetics of ascribing causal responsibility to genotype by the use of heritability estimates has been heavily criticized over the years. It has been argued that these estimates are rarely valid and do not trace genetic causation. Recent contributions strike back at this criticism. I present and discuss two opposing views on these matters represented by Richard Lewontin and Neven Sesardic. I suggest that the conflicting perspectives are based in differing concepts of genetic causation and differing motivations and contexts of discussion. I use the distinction between structuring and triggering causes to clarify the basis for the opposing views.

The “usual story” regarding molecular chemistry is that it is roughly an application of quantum mechanics. That is to say, quantum mechanics supplies everything necessary and sufficient, both ontologically and epistemologically, to reduce molecular chemistry to quantum mechanics. This is a reductive story, to be sure, but a key explanatory element of molecular chemistry, namely molecular structure, is absent from the quantum realm. On the other hand, typical characterizations of emergence, such as the unpredictability or inexplicability of molecular structure based on quantum mechanics, do not characterize the relationship between molecular chemistry and quantum mechanics well either. A different scheme for characterizing reduction and emergence is proposed that accommodates the relationship between quantum mechanics and molecular chemistry and some initial objections to the scheme are considered.

The present paper examines the role of exact results in the theory of many-body physics, and specifically the example of the Mermin-Wagner theorem, a rigorous result concerning the absence of phase transitions in low-dimensional systems. While the theorem has been shown to hold for a wide range of many-body models, it is frequently ‘violated’ by results derived from the same models using numerical techniques. This raises the question of how scientists regulate their theoretical commitments in such cases, given that the models, too, are often described as approximations to the underlying ‘full’ many-body problem.

Albert (2000) provides a sketch of an entropy account of the causal and counterfactual asymmetries. This paper critically examines a proposal that may be thought to fill in some of the lacunae in Albert's account.

In this paper I examine Albert's (2000) claim that the low entropy state of the early universe is sufficient to explain irreversible thermodynamic phenomena. In particular, I argue that conditionalizing on the initial state of the universe does not have the explanatory power it is presumed to have. I present several arguments to the effect that Albert's ‘past hypothesis’ alone cannot justify the belief in past nonequilibrium conditions or ground the veracity of records of the past.

In this paper we argue that the emergence of the classical world from the underlying quantum reality involves two elements: self-induced decoherence and macroscopicity. Self-induced decoherence does not require the openness of the system and its interaction with the environment: a single closed system can decohere when its Hamiltonian has continuous spectrum. We show that, if the system is macroscopic enough, after self-induced decoherence it can be described as an ensemble of classical distributions weighted by their corresponding probabilities. We also argue that classicality is an emergent property that arises when the behavior of the system is described from an observational perspective.

Does the need to find a quantum theory of gravity imply that the gravitational field must be quantized? Physicists working in quantum gravity routinely assume an affirmative answer, often without being aware of the metaphysical commitments that tend to underlie this assumption. The ambition of this article is to probe these commitments and to analyze some recently adduced physical—as opposed to metaphysical—arguments pertinent to the issue of quantization. While there exist good reasons to quantize gravity, as this analysis will show, alternative approaches to gravity challenge the received wisdom. These renegade approaches do not regard gravity as a fundamental force, but rather as effective, i.e., as merely supervening on fundamental physics. I will urge that these alternative accounts at least prove the tenability of an opposition to quantization.

Modal interpretations are hidden-variable, no-collapse interpretations of quantum mechanics that were designed to solve the measurement problem and reconcile this theory with relativity. Yet, as no-go theorems by Dickson and Clifton (1998), Arntzenius (1998) and Myrvold (2002) demonstrate, current modal interpretations are incompatible with relativity. In the mainstream modal interpretations, properties of composite systems are generally unrelated to the properties of their subsystems. We propose holistic and relational interpretations of properties to explain this failure of property composition. Based on these interpretations, we consider strategies for circumventing Myrvold's theorem, which are also effective against the other two theorems.

This paper is concerned with the possibility and nature of relativistic hidden-variable formulations of quantum mechanics. Both ad hoc teleological constructions and frame-dependent constructions of spacetime maps are considered. While frame-dependent constructions are clearly preferable, a many-maps theory based on such constructions fails to provide dynamical explanations for local quantum events. Here the hidden-variable dynamics used in the frame-dependent constructions is just a rule that serves to characterize the set of all possible spacetime maps. While not having dynamical explanations of the values of quantum-mechanical measurement records is a significant cost, it may prove too much to ask for dynamical explanations in relativistic quantum mechanics.

Geometry was a main source of inspiration for Carnap's conventionalism. Taking Poincaré as his witness, Carnap asserted in his dissertation Der Raum ([1922] 1978) that the metrical structure of space is conventional while the underlying topological structure describes ‘objective’ facts. With only minor modifications he stuck to this account throughout his life. The aim of this paper is to disprove Carnap's contention by invoking some classical theorems of differential topology. It is shown that his metrical conventionalism is indefensible for mathematical reasons. This implies that the relation between topology and geometry cannot be conceptualized as analogous to the relation between the meaning of a proposition and its expression in some language as the logical empiricists used to say.

Two central and well-known philosophical goals of the logical empiricists are the unification of science and the elimination of metaphysics. Textual analysis shows, however, that these two apparently distinct planks of the logical empiricist party platform are actually intimately related. From the 1920s through 1950, one abiding criterion for judging whether an apparently declarative assertion or descriptive term is metaphysical is that that assertion or term cannot be incorporated into a language of unified science. I explore various versions of this criterion throughout the works of Carnap and Neurath.

In the nineteenth century, William Whewell claimed that his confirmation criterion of consilience was a truth-guarantor: we could, he believed, be certain that a consilient theory was true. Since that time Whewell has been much ridiculed for this claim by critics such as J. S. Mill and Bas van Fraassen. I have argued elsewhere that, while Whewell's claim that consilience can guarantee the truth of a theory is clearly wrong, consilience is indeed quite useful as a confirmation criterion (Snyder 2005). Here I will show that, even when consilience gives evidence for a theory that turns out to be false, there is an important sense in which consilience shows that the theory has captured something correct about the natural-kind structure of the physical world. Whewell was therefore correct to claim that consilience provides a “criterion of reality” (Whewell [1847] 1967, vol. 2, 68). Consilience provides this by giving justification for the claim that we have really ‘cut nature at its causal joints’, to adapt Plato's famous phrase. Because of this, consilience can play a role in an argument for scientific realism.

The kinds of models discussed in this paper function as measuring instruments. We will concentrate on two necessary steps for measurement: (1) one should search for a mathematical representation of the phenomenon; (2) this representation about the phenomenon should cover an invariant relationship between properties of the phenomenon to be measured and observable associated attributes of a measuring instrument. Therefore, the measuring instrument should function as a nomological machine. However, invariant relationships are not necessarily ceteris paribus regularities, but could also occur when the influence of the environment is negligible. Then we are able to achieve accurate measurements outside the laboratory.

Starting with a discussion of what I call ‘Koyré's paradox of conceptual novelty’, I introduce the ideas of Damerow et al. on the establishment of classical mechanics in Galileo's work. I then argue that although their view on the nature of Galileo's conceptual innovation is convincing, it misses an essential element: Galileo's use of the experiments described in the first day of the Two New Sciences. I describe these experiments and analyze their function. Central to my analysis is the idea that Galileo's pendulum experiments serve to secure the reference of his theoretical models in actually occurring cases of free fall. In this way, Galileo's experiments constitute an essential part of the meaning of the new concepts of classical mechanics.

I develop a concept of observability that pertains to qualities rather than objects: A quality is observable if it can be registered by human sensation (possibly with the aid of instruments) without involving optional interpretations. This concept supports a better description of observations in science and everyday life than the object-based observability concepts presupposing causal information-transfer from the object to the observer. It also allows a rehabilitation of the traditional empiricist distinction between observations and their interpretations, but without a presumption that observations are infallible. Using this concept of observability, I also propose a re-formulation of constructive empiricism that is easier to defend against realist attacks, while open to reasonable realist intuitions.

Philosophers of experiment have acknowledged that experiments are often more than mere hypothesis-tests, once thought to be an experiment's exclusive calling. Drawing on examples from contemporary biology, I make an additional amendment to our understanding of experiment by examining the way that `wide' instrumentation can, for reasons of efficiency, lead scientists away from traditional hypothesis-directed methods of experimentation and towards exploratory methods.