Scoop Review of Books

What’s Philosophy Accomplished?

Rationis Defensor: Essays in Honour of Colin Cheyne Edited by James Maclaurin (Springer, €99.)

Reviewed by Charles Gibson

Cover Rationis Defensor

People often ask me what philosophers have accomplished in the last hundred years. The popular conception is that while science seems to be advancing technology and knowledge daily, philosophy is still a pastime for people who wish to relax in their armchairs and debate the existence of God. This portrait of philosophy is a false one, but convincing people can be difficult. So from now on when somebody asks me what philosophers have been up to, I can direct them to a copy of Rationis Defensor.
This collection of recent philosophical papers, edited by head of Otago University’s philosophy department, James Maclaurin, provides a nice selection of the current debates and crucial issues at play in philosophy. It includes a diverse sampling of philosophical disciplines addressing issues in epistemology (theory of knowledge), philosophy of science, metaphysics and philosophical logic.

‘Rationis Defensor,’ which means defender of rationality, is the motto of senior lecturer and former head of the Otago department Colin Cheyne in whose honour these essays were collected. Cheyne’s contribution to philosophy has been both international, through his publications, and local through his efforts to instil good philosophical habits in his students. As such this collection of papers reflects both his style and quality of philosophy.

The papers are written from within the analytic tradition, focusing on clear argumentation and careful use of terms. The analytic style is exemplified in such papers as Gregory Dawes’ ‘Justified Believing: Avoiding the Paradox’, and James Maclaurin’s ‘Universal Darwinism: Its Scope and Limits’, who both formalise the main philosophical issue of their paper as inconsistent propositions. The analytic quality is shown in such papers as ‘Kant on Experiment’ by Alberto Vanzo, who writes on the role of experiment in early modern philosophy, and Andrew Moore’s ‘The Buck-Passing Stops Here’, who discusses which properties should determine morality. Both of these papers are notable for their fluid prose and graceful argumentation.

As a defender of rationality Cheyne maintains an approach to philosophy with both feet firmly on the ground. Rationis Defensor reflects Cheyne’s common-sense approach, with several of the authors arguing against philosophical doctrines which seem far-fetched. In her paper ‘Propositions: Truth vs. Existence’, Heather Dyke outlines an objection to recent approaches to problems in metaphysics. As an example a simple truth theory states that truth is correspondence. The sentence ‘Snow is white’ is true if and only if snow is white. However past truths such as ‘Lincoln was president of America’ seem not to have a current state of affairs to correspond to. One approach to this problem is to argue that the past is a set of propositions which form the truthmaker for the Lincoln sentence. Dyke argues against taking this notion too far: while she agrees that “proposition talk” has benefits, she denies that we need to think of propositions as actually existing in the robust sense.

This commitment to common sense is also apparent in Charles Pigden and Rebecca Entwisle’s paper, ‘Spread Worlds, Plenitude and Modal Realism: A Problem for David Lewis’, which challenges concrete modal realism. Modal realism is the view that a parallel universe, which is completely isolated from our own, exists for every logical possibility there is. The idea of parallel universes is not completely crazy, but it becomes far-fetched fairly quickly if a universe must exist for every logical possibility. For example, if there’s nothing logically impossible about what goes on in Star Wars, then there must be a parallel universe in which the events depicted in Star Wars are historical fact rather than entertaining fiction. Concrete modal realism implies that Jar Jar Binks is a real person!

However, not all of the papers in the collection align with Cheyne’s own views. Alan Musgrave, in ‘Getting over Gettier’, writes on his disagreement with Cheyne. Musgrave argues that Gettier’s thought experiments do not refute the traditional definition of knowledge as justified true belief. This has been their sharpest point of debate over the years in which they have been colleagues.

Whether or not the conclusions align with Cheyne’s views is beside the point. The authors have constructed strong essays in his honour and the collection is held together nicely by themes of common sense and clear argumentation. One particularly intriguing and pertinent paper is ‘The Future of Utilitarianism’ by Tim Mulgan, which explores how ethics would be affected in a post climate change world, asking compelling questions about obligations we have now to future generations.

Harry Potter, Darwin and Some Logic

My initial reaction when I thumbed through Rationis Defensor was surprise. Typically when I pick up a collection of papers I find one or two titles in the contents which stand out as interesting. However when I looked through the contents of this collection, nearly every title intrigued me. All the papers discussed fascinating topics and many provoked questions in me which I had not considered before. Although a review of this kind can’t do justice to the specialist work in this collection, it’s nevertheless worth taking a closer look at a representative few papers, one each from the major groupings of epistemology, philosophy of science, and logic.

Literature and Truthfulness

From epistemology Gregory Currie, in ‘Literature and truthfulness’, asks to what extent truth plays a role in literature and wonders how confident we can be that fiction accurately captures human behaviour. Take the Harry Potter series: If I were to tell you that Harry really does exist and casts spells, you would likely claim that this statement was false. But if I said that Harry has a scar on his head, you would likely claim that this statement was true. On a technical reading both statements are false because Harry Potter does not exist. He is fictional. Fiction, it seems, is comprised of false statements. They describe a fictional world but not our world.

However there remain ways in which fiction appears to contain truths. We can appreciate a piece of fiction because it seems to accurately capture human nature or seems very real. Shakespeare particularly had a talent for this. Alternatively we can criticise a work of fiction for falsely representing how people actually are. Currie gives us the powerful example of the latter in By Love Possessed, a book which was criticised on grounds of “racism, snobbery and general conservativism”. The claims in this book were false, but were also criticised for their falseness. Currie’s conclusion is a fair one, rejecting the idea that truth is irrelevant to criticism, and arguing that literature can accurately capture the human condition; but he accepts that we don’t yet have a clear picture of what human nature is.

Universal Darwinism

From philosophy of science comes ‘Universal Darwinism: Its Scope and Limits’ by James Maclaurin, in which Maclaurin discusses the growth of evolutionary theory beyond its traditional boundaries. The theory of natural selection was meant to apply to the evolution of species. It uses three Darwinian principles that attempt to capture this niche. For natural selection to occur populations must vary, that variation must be inheritable and it must have an effect on fitness. Consider a population of giraffes. There is a variance in the length of their necks, the giraffes with the longest necks can consume the most leaves from the tree tops and the ones who do consume the most leaves have a far better chance of surviving and reproducing.

However the three Darwinian principles are general enough that they apply to far more than just species development. From a prima facie point of view, language seems to also be a product of natural selection. We have inheritance from person to person, a huge amount of variance and fitness to the environment. When an environmental pressure such as cell phone use is introduced, language adapts to it. For many years text messages were cumbersome to write and allowed for only 160 characters per message. Hence words became shortened to acronyms such as ‘btw’ for ‘by the way’ and spelling became much more efficient. ‘What are you up to?’ is more commonly expressed as ‘Wot r u up 2?’ or ‘Wuu2?’.

The core of the tension here is that Darwin’s theory of natural selection was never intended to apply to a range of topics this broad. It doesn’t seem totally strange to talk of language evolving, but what about technology or mechanics? Televisions have been rapidly changing over the last couple of decades to meet ‘environmental pressures’ such as picture quality, weight, space consumption and appearance. However it still seems a little strange to talk of televisions evolving. Maclaurin’s paper looks at some attempts to alter the Darwinian criteria for the purpose of restricting natural selection talk of genetic inheritance. He considers five different approaches to this end: extended phenotypes, memes, dual inheritance, developmental systems theory, and extended replicator theory, many of which Richard Dawkins has argued heavily for. After explaining and treating these proposals Maclaurin applies an analogous problem from philosophy of mind to argue that attempts to produce determinate conditions for what cases are genuine instances of natural selection will fail.

A Neglected Reply to Prior’s Dilemma

The final paper I’ll look at here – J.C. Beall’s ‘A Neglected Reply to Prior’s Dilemma’ – may only be of interest to readers with a fascination for logic, but nevertheless it is well worth the effort. First, a bit of background: Logical systems tend to focus around some concept of validity, a set of rules which preserve truth from the premises of an argument (the points in the argument which support the conclusion) to the conclusion. By ‘preserve’, I mean that an argument is valid if and only if it is impossible for the premises to be true and the conclusion false. This technical meaning of ‘validity’ differs from the common use of the term. Statements such as ‘that is a valid point’ typically mean things like ‘that is a good/ fair/ correct point’. In logic, by contrast, to say that an argument is valid is simply to say that it is impossible for the premises to be true and the conclusion false.

With this definition in mind there are certain inferences that can never be made in a valid argument. These are known as implication barriers. One such barrier is the no ‘ought’ from ‘is’ rule. Given a statement like ‘it is the case that people donate to charity’ you cannot validly infer ‘it ought to be the case that people donate to charity’. The barrier prevents us from validly inferring ought statements from purely is statements. A big challenge to this barrier came from Arthur Prior and his use of ‘or’ statements. These types of sentences are disjunctive and only require one true disjunct for the whole thing to be true. If it is true that the grass is green then it is also true that the grass is green or the grass is purple. So Prior produces a valid argument from ‘it is the case that X’ to ‘it is the case that X or it ought to be the case that Y.’

Beall offers a reply to this claim by using a three-valued logic system. Typically logic systems use a two-valued system. Assign 1 to a sentence for truth and 0 to sentence if it is false. Three valued systems allow for an extra value .5 which may represent both true and false or neither true nor false. Beall applies this concept to Prior’s argument. In the three valued logic system which Beall uses, ‘P’ fails to imply ‘P or Q’ because the disjunct can end up taking the value .5. Hence the step from ‘P’ to ‘P or Q’ “can take you from truth to untruth”.

The reader may find it a little strange that Beall uses a different system of logic as a counterexample to an apparently valid inference. But this type of reply has become common in modern philosophy. Much of the interesting research in logic has been on small changes to the accepted classical system. Among other modifications, some of these systems allow for extra truth values. A logic which allows for paradoxical sentences such as ‘this sentence is false’ to be neither true nor false is known as paracomplete and a logic which allows for it to be both true and false is known as paraconsistent. These systems are as controversial as they are popular but if the reader has any interest in logic then they will likely find themselves fascinated by the effects these small tweaks to classical logic have. Beall’s paper is a good place to gauge your interest in this subject.

Challenging, Provoking

These three accounts are not meant to be robust philosophical reports on what are quite complex pieces of philosophical work. Rather, they are mere snapshots of the papers which aim to give a flavour of what to expect, should you decide to venture down the rabbit hole of Rationis Defensor. In this collection you will find plenty to pique your interest. Two notable strengths are the variety of topics discussed and the fact that much of the research is cutting edge. The latter, though, also means some of the papers can be tough going for those not steeped in the most recent scholarship. (If you get stuck, I recommend the online Stanford Encylopedia of Philosophy Thankfully, the authors go to great lengths to set out their research clearly and make it plain from the outset what they are arguing and why. As a reader I found that even when I became lost, the clear structuring made it much easier to identify exactly where I’d lost my way and how to find it again.

Rationis Defensor is a collection of papers created in honour of Colin Cheyne. To that end the editors have succeeded wonderfully. The book honours Cheyne both through the diversity of the topics and the clear, precise style which the authors employ. To Cheyne this collection of papers is tribute to the quality of his work and the lasting impression he has left on his colleagues and students.

To me, this collection was a delightful trip down the philosophical rabbit hole. A trip which provoked unconsidered questions in me whilst retaining a firm grasp on common sense throughout. To the potential reader this collection contains a solid sampling of modern philosophy that showcases a strong defence of rationality and the progress made in the philosophical method. The papers can be challenging in places. But the joy of tumbling down the rabbit hole is that every so often you get snagged on a root. If you are interested in reading an example of what philosophers have been up to lately then pick up a copy of Rationis Defensor. You will not be disappointed.


Charles Gibson is a postgraduate student at the University of Otago, New Zealand. He is currently researching a Master’s project on ethical issues in digital piracy. His primary research interests are logic, philosophy of science and ethics. In his spare time he enjoys digital entertainment and gathers philosophical examples from pop culture to aid in tutoring.