In this book, Matthew Fulkerson offers a thorough study of human touch. He focusses on issues pertaining to the philosophy of psychology, and avoids explicitly metaphysical debates about the ontology of tangible qualities, or about representational (or phenomenal) nature of perceptual experience. What interests him is “understanding how the tactual system represents the qualities that are attributed directly to objects” (113).

The work is empirically informed, and the dialectical framework is remarkably clear and useful. Each step is precisely argued and grounded on very interesting philosophical distinctions and conceptual hierarchies (especially in Chapters 3 and 5). Though the study is specialized, it is not narrow in scope and philosophical ambition, for Fulkerson uses the results of his enquiries on touch to tackle more general issues, like the nature of the relation between perception and action, between perception and space, and the role of affects in our explanations of perceptual expertise.

Fulkerson argues a major thesis (Chapters 1, 2, 3 and 5) and offers insightful accounts of topics which, although they are not central to the thesis, allow the reader to grasp the explanatory relevance of the major thesis (Chapters 4, 6, 7, on bodily awareness, distal touch and pleasant touch).

According to the major thesis, touch, though complex, is (a) unitary, (b) in a peculiar way.

1. a) Touch is not a hybrid experience (with separate parts pertaining to heterogeneous sensory subsystems, like heat-sense, pressure-sense, and the like). Rather, it is a unisensory experience. A unisensory experience is feature-binding, which is a necessary but not sufficient condition for unisensory experience: “unisensory experiences involve the direct assignment of features to perceptual objects whereas multisensory experiences involve some higher-level relation between these bound experiences” (33).

2. b) Touch is unitary in a peculiar way. By this, the author means that the assignment (or distribution) of features to perceptual objects depends on exploratory procedures (EPs), a concept which he borrows from experimental psychologists Susan Lederman and Roberta Klatzky. The bound structure (features attributed to perceptual objects) is not different from other senses, but the modalities of distribution are, the author claims, unique. “Our exploratory movements determine the range of tangible features that become grouped together. If I lightly touch an object with only the tip of my little finger, I cannot feel its heft, or global shape, or overall size. I would feel other features, perhaps thermal properties and hardness” (54). Thus, the assignment of a feature of a certain type is constrained by some standard exploratory procedure. We do not have the same modalities of distribution in other senses.

I am not sure, however, whether this criterion justifies drawing such a sharp line between touch and the other senses. For example, the attribution of a colour to an object (x has the colour blue) depends, in a certain way, on actions. Imagine I am contemplating a blue colour, but my field of vision is so narrowed that I cannot see that the blue I am contemplating is the blue of a blue sheet of paper. I would be unable to predicate ‘blue’ to an object (referred demonstratively) if I was unable to make exploratory movements with my eyes. I cannot see why movements of the eyes should not “determine which features get grouped and allow us to select certain features for more precise extraction” (57).

We can accept that what makes touch different is that the relation between exploratory procedures and tangible features is central for any philosophical study of touch, while this is maybe not the case with vision.

Tactual features are intensive (Chapter 5), that is, they “involve a single qualitative dimension that varies in intensity” (114). This wood is more or less rough. To put it in more classical words, touch is qualitative rather than quantitative. Tactual features are temporally, rather than spatially, extended. Even if touch provides us with a representation of spatial properties, this is secondary. Intensive features come first. The way they are distributed may result in intrinsic spatial properties (being round, square, as opposed to relational spatial properties—being of a certain size, being close to or far from).

According to Chapter 4, touch depends informationally on bodily awareness. That is, we do not have to be explicitly aware of our bodily states to be able to tactually perceive that x is F, but information generated by the body, by our bodily states is crucial to tactual experiences (“bodily awareness is … an important node in the informational network” (95)), as is information generated by any item with which our body is involved in an informational relation.

This is the topic of Chapter 6, on distal touch. If we understand the complexity of touch, and the essential activity and link to space and environment, we should not be surprised by the idea that, even if touch is a connection sense, it is distal, that is, able to bear on objects which are not in direct (even apparently) contact with our skin, to “stretch out beyond the limits of our body to objects and features located in the distant environment” (7).

In Chapter 7, Fulkerson argues that, when touch brings a pleasant experience, it is not an objective feature: “pleasant touch is best understood as a subpersonal way of evaluating tactual features, an experiential modification of tactual incoming information” (174).

In spite of the few reservations I have made, I recommend this enjoyable book to anyone interested in the philosophy of perception. The method is clear. The information is complete, and the study is, again, thorough. We have only to hope more studies like it will enrich and deepen our vision of perception and of the contribution of the different modalities to our affective, emotive and epistemic lives.