Almost 10 years ago, Robert Lurz published The Philosophy of Animal Minds (Cambridge University Press, 2009). At the time, it was the only volume to collect the work of philosophers on the challenging empirical, conceptual, and methodological questions that arise when we try to think systematically about the mental lives of nonhuman beings. Philosophers have paid increasing attention to animal minds in the intervening years, but it’s still the case that there are hardly any books devoted to this topic, and apart from Kristin Andrews The Animal Mind (Routledge, 2014), there aren’t any that try to provide a comprehensive overview of the problems and positions in, as well as the potential futures for, the growing literature. In this context, The Routledge Handbook of Philosophy of Animal Minds is a particularly welcome volume, as it’s exactly what you would want such a book to be: on the one hand, a wide-ranging and accessible survey of the empirical and philosophical terrain; on the other, a collection of fascinating and provocative arguments that genuinely advance the literature, providing a touchstone for future conversations.

The book has eight parts: mental representation; reasoning and metacognition; consciousness; mindreading; communication; social cognition and culture; association, simplicity, and modeling; and ethics. This means that the authors cover an enormous amount of ground. There are essays on whether animals perceive colors that we don’t, on whether fish have phenomenal consciousness, on the kinds of mental states that are required to generate semantic content, and the importance of empathy in animal ethics. There is no way to do justice to such a rich volume in the space available, so I will simply draw attention to two particularly striking contributions, as they jointly illustrate much of what’s so challenging about this field.

The first is from Christoph Hoerl and Teresa McCormack, who consider the question of whether animals can engage in mental time travel. That is, are there any nonhuman animals who had the capacity to recall past events? It might seem obvious that animals do have this capacity, based on the way that they learn from their experiences. Squirrels, for instance, plainly remember – in some sense of that phrase – where they stored food, as evinced by the fact that they are able to revisit their caches. However, as the authors point out, it isn’t obvious that this is the right conclusion to draw. Animals could well remember by representing past events, but they could also simply engage in “temporal updating.” On the latter approach, an individual animal only has a model of its current environment, not of any past ones, and it simply updates the model based on the information that it gleans from the environment. So, for instance, a squirrel might not be able to revisit the past event where it hid acorns in a knot of a tree, but it may, as a result of having hid those acorns, now have a model of its environment that includes acorns at a particular location.

How might we tell whether animals recall via phenomenological representations of past events? Hoerl and McCormack argue that it’s a mistake to focus on the behavior described above, which won’t help us settle the dispute. Instead, they recommend trying to assess whether any animals have event-independent thought about times – i.e., whether they think about different times as akin to locations to which events can be assigned. The authors point out, quite surprisingly, that even great apes don’t appear to have this ability, based on a study that assessed whether apes could solve a problem that required being able to think about two possible outcomes of a system. This sort of outcome is remarkable, and it stands as an important reminder of the temptation to anthropomorphize animals, explaining their behavior using the mechanisms that appear to explain our own, without sufficiently careful attention to the limits of their abilities.

A second standout contribution is by Simon Fitzpatrick, who criticizes Morgan’s Canon. According to that methodological principle: “In no case may we interpret action as the outcome of the exercise of a higher psychical faculty, if it can be interpreted as the outcome of the exercise of one which stands lower in the psychological scale” (437). And, of course, at least at first blush, this is the sort of principle on which Hoerl and McCormack seem to rely. Fitzpatrick distinguishes four ways in which the Canon has been interpreted: the prohibitive reading, which simply opposes higher level psychological explanations; the conservative reading, which dictates that we ought to favor the lower level explanation over the higher level one; the restraining reading, which says that we shouldn’t endorse a higher level explanation when a lower one is available; and the cautionary reading, which offers no specific methodological advice, but simply remind researchers not to make the mistakes that their predecessors made. He goes on to argue that the first three interpretations run into serious trouble: the prohibitive reading turns what should be an empirical issue into a methodological one; the conservative reading overlooks all the non-behavioral evidence that’s relevant to deciding which explanation is best; the restraining reading only tries to avoid one type of error (the mistake of explaining behavior using overly complex cognitive mechanisms, rather than the mistake of using overly simple ones); and given all these other problems, the cautionary reading is likely to be misused. We would be better off, Fitzpatrick argues, simply to attend to all our evidence, and to select the hypothesis that best explains it.

Many of the essays in the Handbook, like the one by Hoerl and McCormack, challenge our tendency to smuggle unwarranted assumptions into our understandings of the studies that have been done on animal cognition, language, emotion, and much more. And Fitzpatrick challenges our tendency to be overly reductive, denying capacities to animals not because the evidence really supports, say, the now-defunct hypothesis that all animal learning can be explained by operant conditioning, but because we are far too concerned not to be “tricked” into believing that animals are as similar to us as they sometimes appear to be. This is the fine line that has to be walked in the philosophy of animal minds. (What’s more, it’s part of what makes it so difficult to do animal ethics in an empirically-informed way. It’s incredibly tempting to skew your interpretation of the empirical results based on your preferred moral conclusion, as seen in so many discussions of the badness of death even in “humane” farms, where claims about animals’ relationships to their own futures are crucial, or the kinds of interests that laboratory animals have, where, e.g., debates about the nature of animal autonomy and sociality are particularly pressing.) The contributors to this volume walk this line with impressive poise, and as a result, this book is certainly one that repays careful study.

© 2018 Bob Fischer

Bob Fischer teaches philosophy at Texas State University. He’s the editor of The Moral Complexities of Eating Meat (Oxford, 2015; with Ben Bramble) and College Ethics: A Reader on Moral Issues That Affect You(Oxford, 2017). He’s also the author of several essays on animal ethics, moral psychology, and the epistemology of modality.