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Matt Farr

University of Cambridge, Department of History and Philosophy of Science, Faculty Member

The University of Queensland, Australia, School of Historical and Philosophical Inquiry (HAPI), Post-Doc

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All my papers are available for free at mattfarr.co.uk. No need to use this site :)

Philosopher of science at Cambridge. Works on time, causation, explanation. etc.

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Papers by Matt Farr

Tim Maudlin, Philosophy of Physics: Space and Time. Princeton, NJ: Princeton University Press (2012), xiv+183 pp., $29.95 (cloth)

Philosophy of Science, 2014

Pre-entanglement shows that individual quantum systems do not possess states

We consider an experiment in which quantum tomography data is collected before and after an entan... more We consider an experiment in which quantum tomography data is collected before and after an entangling measurement performed on two independently prepared, maximally-mixed ensembles. We show that each sub-ensemble that is, as expected, entangled after the measurement is also entangled before it. We call the latter pre-entanglement. If individual systems possessed quantum states, their independent preparations would mean the sub-ensembles were in separable states prior to the entanglement event. The contradiction can be resolved by assigning states only to ensembles and not individual quantum systems. Pre-entanglement found here at the quantum level makes very doubtful the assumption of preparation independence at the ontic level required for a recent theorem

What’s so special about initial conditions? Understanding the past hypothesis in directionless time

It is often said that the world is explained by laws of nature together with initial conditions. ... more It is often said that the world is explained by laws of nature together with initial conditions. But does that mean initial conditions don’t require further explanation? And does the explanatory role played by initial conditions entail or require that time has a preferred direction? This chapter looks at the use of the ‘initialness defence’ in physics, the idea that initial conditions are intrinsically special in that they don’t require further explanation, unlike the state of the world at other times. Such defences commonly assume a primitive directionality of time to distinguish between initial and final conditions. Using the case study of the time-asymmetry of thermodynamics and the so-called ‘past hypothesis’ — the hypothesis that the early universe was in a state of very low entropy —, I outline and support a deflationary account of the initialness defence that does not pre- suppose a basic directionality of time, and argue that there is a relevant explanatory asymmetry between...

Review of Causation in Science by Yemima Ben-Menahem

Essay review of 'Causation in Science' by Yemima Ben-Menahem (2018, Princeton University ... more

Conventionalism about time direction

Synthese, 2022

In what sense is the direction of time a matter of convention? In The Direction of Time, Hans Rei... more In what sense is the direction of time a matter of convention? In The Direction of Time, Hans Reichenbach makes brief reference to parallels between his views about the status of time’s direction and his conventionalism about geometry. In this article, I: (1) provide a conventionalist account of time direction motivated by a number of Reichenbach’s claims in the book; (2) show how forwards and backwards time can give equivalent descriptions of the world despite the former being the ‘natural’ direction of time; and (3) argue that this offers an important middle-ground position between existing realist and antirealist accounts of the direction of time.

Review of Mathias Frisch's Causal Reasoning in Physics

Review of 'Causal Reasoning in Physics' by Mathias Frisch for British Journal for Philoso... more

Review of Tim Maudlin, "Philosophy of Physics: Space and Time

Temporal Ontology in Perspective

Do non-present things exist? A number of authors have argued that this question lacks substance i... more Do non-present things exist? A number of authors have argued that this question lacks substance in that the rival temporal ontologies—Presentism (non-present things don’t exist) and Eternalism (non-present things exist)— are not properly distinct, and so temporal ontology faces a problem of triviality. The debate has centred on the tense of ‘exists’ and the indexicality of ‘is present’. I show that this needn’t be the case: firstly, one can provide nonindexical criteria of ontological commitment for the di erent temporal ontologies; secondly the resulting formulations of the temporal ontologies are distinguished in terms of their observer-independent, non-indexical structure, showing that triviality is avoided at the level of ontological commitment by removing indexicals. I demonstrate how the resulting account of temporal ontologies relates to standard accounts, and how the resulting account of presentism avoids conceptual problems standardly raised against accounts of presentism. ...

Methods in Science and Metaphysics

While science is taken to differ from non-scientific activities in virtue of its methodology, met... more While science is taken to differ from non-scientific activities in virtue of its methodology, metaphysics is usually defined in terms of its subject matter. However, many traditional questions of metaphysics are addressed in a variety of ways by science, making it difficult to demarcate metaphysics from science solely in terms of their subject matter. Are the methodologies of science and metaphysics sufficiently distinct to act as criteria of demarcation between the two? In this chapter we focus on several important overlaps in the methodologies used within science and metaphysics in order to argue that focusing solely on methodology is insufficient to offer a sharp demarcation between metaphysics and science, and consider the consequences of this for the wider relationship between science and metaphysics.

On the Possibility of Ontological Models of Quantum Mechanics

It is an unresolved question in quantum mechanics whether quantum states apply to individual quan... more It is an unresolved question in quantum mechanics whether quantum states apply to individual quantum systems, or to ensembles of quantum systems. We show by way of a thought experiment that quantum states apply only to ensembles of quantum systems. A further unresolved question is whether quantum systems possess ontic states. If a quantum state is the state of an ensemble, as we claim, the answer to this question is that quantum states are not ontic. However, a notable recent result in quantum foundations shows that if there are any ontic states at all, then the quantum state must be ontic. Collectively, these two results imply that there are no ontic states. We examine the assumptions required for these results, and suggest that the retrospective effect on state preparations by entangling measurements provides good reason for relaxing the assumption of preparation independence at the ontic level.

C‐theories of time: On the adirectionality of time

Philosophy Compass, 2020

The universe is expanding, not contracting. " Many statements of this form appear unambiguously t... more The universe is expanding, not contracting. " Many statements of this form appear unambiguously true; after all, the discovery of the universe's expansion is one of the great triumphs of empirical science. However, the statement is time-directed: the universe expands towards what we call the future; it contracts towards the past. If we deny that time has a direction, should we also deny that the universe is really expanding? This article draws together and discusses what I call 'C-theories' of time-in short, philosophical positions that hold time lacks a direction-from different areas of the literature. I set out the various motivations, aims, and problems for C-theories, and outline different versions of antirealism about the direction of time.

Causation and Time Reversal

The British Journal for the Philosophy of Science, 2017

What would it be for a process to happen backwards in time? Would such a process involve differen... more What would it be for a process to happen backwards in time? Would such a process involve different causal relations? It is common to understand the time reversal invariance of a physical theory in causal terms, such that whatever can happen forwards in time (according to the theory) can also happen backwards in time. This has led many to hold that time reversal symmetry is incompatible with the asymmetry of cause and effect. This paper critiques the causal reading of time reversal. First, I argue that the causal reading requires time-reversal-related models to be understood as representing distinct possible worlds, and on such a reading causal relations are compatible with time reversal symmetry. Second, I argue that the former approach does however raise serious sceptical problems regarding the causal relations of paradigm causal processes, and as a consequence there are overwhelming reasons to prefer a non-causal reading of time reversal whereby time reversal leaves causal relations invariant. On the noncausal reading, time reversal symmetry poses no significant conceptual nor epistemological problems for causation.

Conventional Principles in Science: On the foundations and development of the relativized a priori

Studies in History and Philosophy of Science Part B: Studies in History and Philosophy of Modern Physics, 2015

On A- and B-theoretic elements of branching spacetimes

Synthese, 2011

This paper assesses branching spacetime theories in light of metaphysical considerations concerni... more This paper assesses branching spacetime theories in light of metaphysical considerations concerning time. I present the A, B, and C series in terms of the temporal structure they impose on sets of events, and raise problems for two elements of extant branching spacetime theories-McCall's 'branch attrition', and the 'no backward branching' feature of Belnap's 'branching space-time'-in terms of their respective Aand B-theoretic nature. I argue that McCall's presentation of branch attrition can only be coherently formulated on a model with at least two temporal dimensions, and that this results in severing the link between branch attrition and the flow of time. I argue that 'no backward branching' prohibits Belnap's theory from capturing the modal content of indeterministic physical theories, and results in it ascribing to the world a time-asymmetric modal structure that lacks physical justification.

A Relic of a Bygone Age? Causation, Time Symmetry and the Directionality Argument

Erkenntnis, 2013

Bertrand Russell famously argued that causation is not part of the fundamental physical descripti... more Bertrand Russell famously argued that causation is not part of the fundamental physical description of the world, describing the notion of cause as "a relic of a bygone age" (Russell, 1913, p. 1). This paper assesses one of Russell's arguments for this conclusion: the 'Directionality Argument', which holds that the time symmetry of fundamental physics is inconsistent with the time asymmetry of causation. We claim that the coherence and success of the Directionality Argument crucially depends on the proper interpretation of the 'time symmetry' of fundamental physics as it appears in the argument, and offer two alternative interpretations. We argue that: (1) if 'time symmetry' is understood as the time-reversal invariance of physical theories, then the crucial premise of the Directionality Argument should be rejected; and (2) if 'time symmetry' is understood as the temporally bidirectional nomic dependence relations of physical laws, then the crucial premise of the Directionality Argument is far more plausible. We defend the second reading as continuous with Russell's writings, and consider the consequences of the bidirectionality of nomic dependence relations in physics for the metaphysics of causation.

Perceiving Direction in Directionless Time

Modern physics has provided a range of motivations for holding time to be fundamentally undirecte... more Modern physics has provided a range of motivations for holding time to be fundamentally undirected. But how does a temporally adirectional metaphysics, or ‘C-theory’ of time, fit with the time of experience? In this chapter, I look at what kind of problem human time poses for C-theories. First, I ask whether there is a ‘hard problem’ of human time: whether it is in principle impossible to have the kinds of experience we do in a temporally adirectional world. Second I consider the ‘easy problem’: how specific directed aspects of our temporal experience are to be explained by C-theorists. This leads to a greater issue: is there such a thing as an experience of time direction at all to even be explained? I show how the kinds of experience we have that we typically associate with the idea of time being directed can be accommodated within a directionless picture of time

Explaining temporal qualia

European Journal for Philosophy of Science

Experiences of motion and change are widely taken to have a ‘flow-like’ quality. Call this ‘tempo... more Experiences of motion and change are widely taken to have a ‘flow-like’ quality. Call this ‘temporal qualia’. Temporal qualia are commonly thought to be central to the question of whether time objectively passes: (1) passage realists take temporal passage to be necessary in order for us to have the temporal qualia we do; (2) passage antirealists typically concede that time appears to pass, as though our temporal qualia falsely represent time as passing. I reject both claims and make the case that passage-talk plays no useful explanatory role with respect to temporal qualia, but rather obfuscates what the philosophical problem of temporal qualia is. I offer a ‘reductionist’ account of temporal qualia that makes no reference to the concept of passage and argue that it is well motivated by empirical studies in motion perception.

Causation and Time Reversal

What would it be for a process to happen backwards in time? Would such a process involve differen... more What would it be for a process to happen backwards in time? Would such a process involve different causal relations? It is common to understand the time reversal invariance of a physical theory in causal terms, such that whatever can happen forwards in time (according to the theory) can also happen backwards in time. This has led many to hold that time reversal symmetry is incompatible with the asymmetry of cause and effect. This paper critiques the causal reading of time reversal. First, I argue that the causal reading requires time-reversal-related models to be understood as representing distinct possible worlds, and on such a reading causal relations are compatible with time reversal symmetry. Second, I argue that the former approach does however raise serious sceptical problems regarding the causal relations of paradigm causal processes, and as a consequence there are overwhelming reasons to prefer a non-causal reading of time reversal whereby time reversal leaves causal relations invariant. On the non-causal reading, time reversal symmetry poses no significant conceptual nor epistemological problems for causation.

Temporal Experience, Temporal Passage and the Cognitive Sciences

Philosophy Compass, 2015

Conventional Principles in Science: On the Foundations and Development of the Relativized A Priori

by Milena Ivanova and Matt Farr

The present volume consists of a collection of papers originally presented at the conference Conv... more The present volume consists of a collection of papers originally presented at the conference Conventional Principles in Science, held at the University of Bristol, August 2011, which featured contributions on the history and contemporary development of the notion of 'relativized a priori' principles in science, from Henri Poincaré's conventionalism to Michael Friedman's contemporary defence of the relativized a priori. In Science and Hypothesis, Poincaré assessed the problematic epistemic status of Euclidean geometry and Newton's laws of motion, famously arguing that each has the status of 'convention' in that their justification is neither analytic nor empirical in nature. In The Theory of Relativity and A Priori Knowledge, Hans Reichenbach, in light of the general theory of relativity, proposed an updated notion of the Kantian synthetic a priori to account for the dynamic inter-theoretic status of geometry and other non-empirical physical principles. Reichenbach noted that one may reject the 'necessarily true' aspect of the synthetic a priori whilst preserving the feature of being constitutive of the object of knowledge. Such constitutive principles are theory-relative, as illustrated by the privileged role of non-Euclidean geometry in general relativity theory. This idea of relativized a priori principles in spacetime physics has been analysed and developed at great length in the modern literature in the work of Michael Friedman, in particular the roles played by the light postulate and the equivalence principle – in special and general relativity respectively – in defining the central terms of their respective theories and connecting the abstract mathematical formalism of the theories with their empirical content. The papers in this volume guide the reader through the historical development of conventional and constitutive principles in science, from the foundational work of Poincaré, Reichenbach and others, to contemporary issues and applications of the relativized a priori concerning the notion of measurement, physical possibility, and the interpretation of scientific theories. The first step towards the development of the relativized a priori is taken by Poincaré's modification of the Kantian epistemic categories in order to accommodate the special status of geometry. Given the construction of consistent geometric systems that negate axioms of Euclidean geometry, Poincaré notes that the Kantian idea of Euclidean geometry being necessarily true is not tenable. However, Euclidean geometry does play an important constitutive role in the physical systems in which it is employed, and in this sense retains a key feature of a prioricity. Though geometry is constitutive, it can no longer be regarded as uniquely imposed upon us since we are left with freedom to employ distinct geometries.

Tim Maudlin, Philosophy of Physics: Space and Time. Princeton, NJ: Princeton University Press (2012), xiv+183 pp., $29.95 (cloth)

Philosophy of Science, 2014

Pre-entanglement shows that individual quantum systems do not possess states

We consider an experiment in which quantum tomography data is collected before and after an entan... more We consider an experiment in which quantum tomography data is collected before and after an entangling measurement performed on two independently prepared, maximally-mixed ensembles. We show that each sub-ensemble that is, as expected, entangled after the measurement is also entangled before it. We call the latter pre-entanglement. If individual systems possessed quantum states, their independent preparations would mean the sub-ensembles were in separable states prior to the entanglement event. The contradiction can be resolved by assigning states only to ensembles and not individual quantum systems. Pre-entanglement found here at the quantum level makes very doubtful the assumption of preparation independence at the ontic level required for a recent theorem

What’s so special about initial conditions? Understanding the past hypothesis in directionless time

It is often said that the world is explained by laws of nature together with initial conditions. ... more It is often said that the world is explained by laws of nature together with initial conditions. But does that mean initial conditions don’t require further explanation? And does the explanatory role played by initial conditions entail or require that time has a preferred direction? This chapter looks at the use of the ‘initialness defence’ in physics, the idea that initial conditions are intrinsically special in that they don’t require further explanation, unlike the state of the world at other times. Such defences commonly assume a primitive directionality of time to distinguish between initial and final conditions. Using the case study of the time-asymmetry of thermodynamics and the so-called ‘past hypothesis’ — the hypothesis that the early universe was in a state of very low entropy —, I outline and support a deflationary account of the initialness defence that does not pre- suppose a basic directionality of time, and argue that there is a relevant explanatory asymmetry between...

Review of Causation in Science by Yemima Ben-Menahem

Essay review of 'Causation in Science' by Yemima Ben-Menahem (2018, Princeton University ... more

Conventionalism about time direction

Synthese, 2022

In what sense is the direction of time a matter of convention? In The Direction of Time, Hans Rei... more In what sense is the direction of time a matter of convention? In The Direction of Time, Hans Reichenbach makes brief reference to parallels between his views about the status of time’s direction and his conventionalism about geometry. In this article, I: (1) provide a conventionalist account of time direction motivated by a number of Reichenbach’s claims in the book; (2) show how forwards and backwards time can give equivalent descriptions of the world despite the former being the ‘natural’ direction of time; and (3) argue that this offers an important middle-ground position between existing realist and antirealist accounts of the direction of time.

Review of Mathias Frisch's Causal Reasoning in Physics

Review of 'Causal Reasoning in Physics' by Mathias Frisch for British Journal for Philoso... more

Review of Tim Maudlin, "Philosophy of Physics: Space and Time

Temporal Ontology in Perspective

Do non-present things exist? A number of authors have argued that this question lacks substance i... more Do non-present things exist? A number of authors have argued that this question lacks substance in that the rival temporal ontologies—Presentism (non-present things don’t exist) and Eternalism (non-present things exist)— are not properly distinct, and so temporal ontology faces a problem of triviality. The debate has centred on the tense of ‘exists’ and the indexicality of ‘is present’. I show that this needn’t be the case: firstly, one can provide nonindexical criteria of ontological commitment for the di erent temporal ontologies; secondly the resulting formulations of the temporal ontologies are distinguished in terms of their observer-independent, non-indexical structure, showing that triviality is avoided at the level of ontological commitment by removing indexicals. I demonstrate how the resulting account of temporal ontologies relates to standard accounts, and how the resulting account of presentism avoids conceptual problems standardly raised against accounts of presentism. ...

Methods in Science and Metaphysics

While science is taken to differ from non-scientific activities in virtue of its methodology, met... more While science is taken to differ from non-scientific activities in virtue of its methodology, metaphysics is usually defined in terms of its subject matter. However, many traditional questions of metaphysics are addressed in a variety of ways by science, making it difficult to demarcate metaphysics from science solely in terms of their subject matter. Are the methodologies of science and metaphysics sufficiently distinct to act as criteria of demarcation between the two? In this chapter we focus on several important overlaps in the methodologies used within science and metaphysics in order to argue that focusing solely on methodology is insufficient to offer a sharp demarcation between metaphysics and science, and consider the consequences of this for the wider relationship between science and metaphysics.

On the Possibility of Ontological Models of Quantum Mechanics

It is an unresolved question in quantum mechanics whether quantum states apply to individual quan... more It is an unresolved question in quantum mechanics whether quantum states apply to individual quantum systems, or to ensembles of quantum systems. We show by way of a thought experiment that quantum states apply only to ensembles of quantum systems. A further unresolved question is whether quantum systems possess ontic states. If a quantum state is the state of an ensemble, as we claim, the answer to this question is that quantum states are not ontic. However, a notable recent result in quantum foundations shows that if there are any ontic states at all, then the quantum state must be ontic. Collectively, these two results imply that there are no ontic states. We examine the assumptions required for these results, and suggest that the retrospective effect on state preparations by entangling measurements provides good reason for relaxing the assumption of preparation independence at the ontic level.

C‐theories of time: On the adirectionality of time

Philosophy Compass, 2020

The universe is expanding, not contracting. " Many statements of this form appear unambiguously t... more The universe is expanding, not contracting. " Many statements of this form appear unambiguously true; after all, the discovery of the universe's expansion is one of the great triumphs of empirical science. However, the statement is time-directed: the universe expands towards what we call the future; it contracts towards the past. If we deny that time has a direction, should we also deny that the universe is really expanding? This article draws together and discusses what I call 'C-theories' of time-in short, philosophical positions that hold time lacks a direction-from different areas of the literature. I set out the various motivations, aims, and problems for C-theories, and outline different versions of antirealism about the direction of time.

Causation and Time Reversal

The British Journal for the Philosophy of Science, 2017

What would it be for a process to happen backwards in time? Would such a process involve differen... more What would it be for a process to happen backwards in time? Would such a process involve different causal relations? It is common to understand the time reversal invariance of a physical theory in causal terms, such that whatever can happen forwards in time (according to the theory) can also happen backwards in time. This has led many to hold that time reversal symmetry is incompatible with the asymmetry of cause and effect. This paper critiques the causal reading of time reversal. First, I argue that the causal reading requires time-reversal-related models to be understood as representing distinct possible worlds, and on such a reading causal relations are compatible with time reversal symmetry. Second, I argue that the former approach does however raise serious sceptical problems regarding the causal relations of paradigm causal processes, and as a consequence there are overwhelming reasons to prefer a non-causal reading of time reversal whereby time reversal leaves causal relations invariant. On the noncausal reading, time reversal symmetry poses no significant conceptual nor epistemological problems for causation.

Conventional Principles in Science: On the foundations and development of the relativized a priori

Studies in History and Philosophy of Science Part B: Studies in History and Philosophy of Modern Physics, 2015

On A- and B-theoretic elements of branching spacetimes

Synthese, 2011

This paper assesses branching spacetime theories in light of metaphysical considerations concerni... more This paper assesses branching spacetime theories in light of metaphysical considerations concerning time. I present the A, B, and C series in terms of the temporal structure they impose on sets of events, and raise problems for two elements of extant branching spacetime theories-McCall's 'branch attrition', and the 'no backward branching' feature of Belnap's 'branching space-time'-in terms of their respective Aand B-theoretic nature. I argue that McCall's presentation of branch attrition can only be coherently formulated on a model with at least two temporal dimensions, and that this results in severing the link between branch attrition and the flow of time. I argue that 'no backward branching' prohibits Belnap's theory from capturing the modal content of indeterministic physical theories, and results in it ascribing to the world a time-asymmetric modal structure that lacks physical justification.

A Relic of a Bygone Age? Causation, Time Symmetry and the Directionality Argument

Erkenntnis, 2013

Bertrand Russell famously argued that causation is not part of the fundamental physical descripti... more Bertrand Russell famously argued that causation is not part of the fundamental physical description of the world, describing the notion of cause as "a relic of a bygone age" (Russell, 1913, p. 1). This paper assesses one of Russell's arguments for this conclusion: the 'Directionality Argument', which holds that the time symmetry of fundamental physics is inconsistent with the time asymmetry of causation. We claim that the coherence and success of the Directionality Argument crucially depends on the proper interpretation of the 'time symmetry' of fundamental physics as it appears in the argument, and offer two alternative interpretations. We argue that: (1) if 'time symmetry' is understood as the time-reversal invariance of physical theories, then the crucial premise of the Directionality Argument should be rejected; and (2) if 'time symmetry' is understood as the temporally bidirectional nomic dependence relations of physical laws, then the crucial premise of the Directionality Argument is far more plausible. We defend the second reading as continuous with Russell's writings, and consider the consequences of the bidirectionality of nomic dependence relations in physics for the metaphysics of causation.

Perceiving Direction in Directionless Time

Modern physics has provided a range of motivations for holding time to be fundamentally undirecte... more Modern physics has provided a range of motivations for holding time to be fundamentally undirected. But how does a temporally adirectional metaphysics, or ‘C-theory’ of time, fit with the time of experience? In this chapter, I look at what kind of problem human time poses for C-theories. First, I ask whether there is a ‘hard problem’ of human time: whether it is in principle impossible to have the kinds of experience we do in a temporally adirectional world. Second I consider the ‘easy problem’: how specific directed aspects of our temporal experience are to be explained by C-theorists. This leads to a greater issue: is there such a thing as an experience of time direction at all to even be explained? I show how the kinds of experience we have that we typically associate with the idea of time being directed can be accommodated within a directionless picture of time

Explaining temporal qualia

European Journal for Philosophy of Science

Experiences of motion and change are widely taken to have a ‘flow-like’ quality. Call this ‘tempo... more Experiences of motion and change are widely taken to have a ‘flow-like’ quality. Call this ‘temporal qualia’. Temporal qualia are commonly thought to be central to the question of whether time objectively passes: (1) passage realists take temporal passage to be necessary in order for us to have the temporal qualia we do; (2) passage antirealists typically concede that time appears to pass, as though our temporal qualia falsely represent time as passing. I reject both claims and make the case that passage-talk plays no useful explanatory role with respect to temporal qualia, but rather obfuscates what the philosophical problem of temporal qualia is. I offer a ‘reductionist’ account of temporal qualia that makes no reference to the concept of passage and argue that it is well motivated by empirical studies in motion perception.

Causation and Time Reversal

What would it be for a process to happen backwards in time? Would such a process involve differen... more What would it be for a process to happen backwards in time? Would such a process involve different causal relations? It is common to understand the time reversal invariance of a physical theory in causal terms, such that whatever can happen forwards in time (according to the theory) can also happen backwards in time. This has led many to hold that time reversal symmetry is incompatible with the asymmetry of cause and effect. This paper critiques the causal reading of time reversal. First, I argue that the causal reading requires time-reversal-related models to be understood as representing distinct possible worlds, and on such a reading causal relations are compatible with time reversal symmetry. Second, I argue that the former approach does however raise serious sceptical problems regarding the causal relations of paradigm causal processes, and as a consequence there are overwhelming reasons to prefer a non-causal reading of time reversal whereby time reversal leaves causal relations invariant. On the non-causal reading, time reversal symmetry poses no significant conceptual nor epistemological problems for causation.

Temporal Experience, Temporal Passage and the Cognitive Sciences

Philosophy Compass, 2015

Conventional Principles in Science: On the Foundations and Development of the Relativized A Priori

by Milena Ivanova and Matt Farr

The present volume consists of a collection of papers originally presented at the conference Conv... more The present volume consists of a collection of papers originally presented at the conference Conventional Principles in Science, held at the University of Bristol, August 2011, which featured contributions on the history and contemporary development of the notion of 'relativized a priori' principles in science, from Henri Poincaré's conventionalism to Michael Friedman's contemporary defence of the relativized a priori. In Science and Hypothesis, Poincaré assessed the problematic epistemic status of Euclidean geometry and Newton's laws of motion, famously arguing that each has the status of 'convention' in that their justification is neither analytic nor empirical in nature. In The Theory of Relativity and A Priori Knowledge, Hans Reichenbach, in light of the general theory of relativity, proposed an updated notion of the Kantian synthetic a priori to account for the dynamic inter-theoretic status of geometry and other non-empirical physical principles. Reichenbach noted that one may reject the 'necessarily true' aspect of the synthetic a priori whilst preserving the feature of being constitutive of the object of knowledge. Such constitutive principles are theory-relative, as illustrated by the privileged role of non-Euclidean geometry in general relativity theory. This idea of relativized a priori principles in spacetime physics has been analysed and developed at great length in the modern literature in the work of Michael Friedman, in particular the roles played by the light postulate and the equivalence principle – in special and general relativity respectively – in defining the central terms of their respective theories and connecting the abstract mathematical formalism of the theories with their empirical content. The papers in this volume guide the reader through the historical development of conventional and constitutive principles in science, from the foundational work of Poincaré, Reichenbach and others, to contemporary issues and applications of the relativized a priori concerning the notion of measurement, physical possibility, and the interpretation of scientific theories. The first step towards the development of the relativized a priori is taken by Poincaré's modification of the Kantian epistemic categories in order to accommodate the special status of geometry. Given the construction of consistent geometric systems that negate axioms of Euclidean geometry, Poincaré notes that the Kantian idea of Euclidean geometry being necessarily true is not tenable. However, Euclidean geometry does play an important constitutive role in the physical systems in which it is employed, and in this sense retains a key feature of a prioricity. Though geometry is constitutive, it can no longer be regarded as uniquely imposed upon us since we are left with freedom to employ distinct geometries.

Review of Mathias Frisch's 'Causal Reasoning in Physics'

C-Theories of Time: On the adirectionality of time

Philosophy Compass, 2020

"The universe is expanding, not contracting. " Many statements of this form appear unambiguously ... more "The universe is expanding, not contracting. " Many statements of this form appear unambiguously true; after all, the discovery of the universe's expansion is one of the great triumphs of empirical science. However, the statement is time-directed: the universe expands towards what we call the future; it contracts towards the past. If we deny that time has a direction, should we also deny that the universe is really expanding? This article draws together and discusses what I call 'C-theories' of time-in short, philosophical positions that hold time lacks a direction-from different areas of the literature. I set out the various motivations, aims, and problems for C-theories, and outline different versions of antirealism about the direction of time.