Scale is part of everybody’s daily experience, and not all of these experiences are as dramatic a mix of fear and awe as Pascal’s positioning of mankind between the infinitely large and the infinitely small. After all, to review a book is a scale experience as well, since the reviewer is no longer dealing with words, sentences, and paragraphs, that is the object of an actual reading, but with larger and totally different units, ideas, claims, and hypotheses (and the reader of a review will obviously go through something similar when entering the book itself – which by the way I can strongly recommend).

Although we are all permanently aware of the presence and importance of scale, our understanding of its remains low, not only because we are so used to it that we neglect to scrutinize its significance, but also because we frame it in the wrong way. Differences of scale are generally envisaged not only from a single viewpoint, that of a given discipline, separated from most other ways of looking and understanding, but also that of “our” homo sapiens viewpoint, who brings everything back to a kind of “this scale” or “meter scale” – the words that Joshua DiCaglio uses to suggest that we tend to express “nonhuman” scales by comparing them with our natural measuring systems. Moreover, we also believe that there exists a kind of analogy between what we observe on our human scale and what we observe on other scales, be they microscopic or telescopic, a way of naturalizing and normalizing scale differences that DiCaglio rightly describes as a way of nonscalar interpretation of scale (the body as a mere collection of cells, for instance, or the universe as a simple collection of stars).

These mistakes are human, all too human, but they miss the real meaning of scale, which some of us experience in certain circumstances and which DiCaglio links with the impression of a fusion with the whole of being, a complete fading out of the boundaries between subject and object, I and the world, body and mind, etc. The author groups these experiences as “mystical”, while also insisting on the fact that it would be a mistake to consider all of them as religious in the traditional sense of the word (the religious experience is just one of the possible forms that a deep scalar experience can take and it is certainly not the universal key to a good understanding of what happens in the encounter between what DiCaglio eventually labels as the coincidence of the I and the Cosmos). Scale, in other words, is not something that exists in itself, it has to be seen as a force that changes both subject and object and above all the relationship between them. In order to grasp what scale actually “does” and to avoid the traditional mistakes in our experience of scale, all of them being nonscalar interpretations of scalar facts, we need a real theory of scale, not a theory of scaling techniques and apparatuses or scaled objects, but a general, nondisciplinary approach that can be applied to any scale experience. This is the ambition of DiCaglio’s book, an enthralling example of science studies (the study of science from the viewpoint of the humanities). In this regard, it is imperative to stress that the author does not identify science studies, as it often occurs, with the critique of science seen as the privileged access to truth, the purely objective study of reality, deprived of “social, personal, or political interests” (p. 199). For him science studies is not an a priori critical approach that positioned as a form of “demystifying, unmasking, or unveiling the practices and claims of science” (id.). While acknowledging the necessity and usefulness of such a critical reading, DiCaglio does not share with many science studies scholars the hegemonic idea of science as merely objective and blinded by empirical research. Instead, he insists on science’s rootedness and amazement and hypothetical reasoning –two forms of fundamental modesty – and thus its possible links with what is at stake in the human experience of scale.

For Scale Theory, scale is essentially transformative. Part One of the book explains the major aspects of this transformation with the help of some basic scalar daily life experiences, which are then enlarged via a certain number of thought experiments. First, scale reconfigures what we observe: what appears on scale A becomes invisible on scale B, which can be bigger or smaller than A, and vice versa. The difference in resolution between these domains is marked by what the authors calls thresholds of observation (a typical mistake of nonscalar reading of scale differences appears for example when we directly link what we observe on scale A with what we observe on scale B). The transformative power of scale involves that the idea of an object or a singular unit has to be fundamentally differentiated: the objects we observe are also part of smaller as well as larger objects we do not observe at the same time but which are not nonexisting for that reason. Second, the differentiated view of the objects does not refer to the object itself (when we do no longer see the trees of a forest when we look from a larger distance, that does not mean that the trees themselves have changed), but to the distance between the observing eye or the observing apparatuses and the object: “scale is created only by the relationship between […] two very different perspectives” (p. 29). More technically speaking: “scale is the relation between one “over there” and another “over here” (p. 32). This new difference has major consequences for the experiencing subject, who ceases to be a single unit; the “I” can no longer identify with one of the two scalar perspectives; instead, the “I” must identify with both of them (if not, the scalar experiences degenerates into a nonscalar one). Third, the scalar experience also has a powerful cognitive dimension that helps move beyond the limited range of the single homo sapiens experience. The scale experience can be scaled itself, so to speak, it produces forms of knowledge that can be stored, memorized, taught, interpreted etc. and therefore supersede any immediate empirical observation, scalar or nonscalar. The result of this cognitive dimension of the scale experience induces the increasing complexification of the possible relationships between object(s) and subject(s).

Part Two of the book covers a more philosophical approach of the basic notions involved by scale theory: subject, object, and of course the shifting relations between them. Quite logically, given the nondual horizon of his scalar thinking, DiCaglio relies here and in other parts of the book as much on non-Western as on Western concepts and ways of thinking, which he not only confronts and compares, but brings together in such a way that their differences become less apparent and important than their similarities. He fluently moves back and forth between Western metaphysics and Buddhist philosophy, for instance, clearly stressing how various thinkers and traditions have tried to come to terms with the scalar experience, each with their own concepts, their own illuminations and their own limitations. Of particular interest is here the critical reading of posthumanism and transhumanism, which definitely fall within the scope of scale theory, but which are not always free of certain forms of nonscalar pars pro toto reasoning. Of similar interest is the discussion on scaling as an expression of power (cartography is here a case in point, which DiCaglio subtly rereads as a form of paradoxically nonscalar thinking, given the pervading role of the “meter scale”, the difficulty of acknowledging questions of unknowability and multiplicity), and the difficulties one may have in conceptualizing the way in which scalar objects, subjects, and relations interact at various levels (the author frequently questions easy posthuman identifications between levels and scales, while also being very critical of exaggerated constructivist approaches of science and facts). At the same time, and this is not a surprise either, DiCaglio pays close attention to the mystical writings of Philip K. Dick, a part of Dick’s oeuvre that is often discarded as quasi-nonsense, or at least as largely uninteresting in comparison with his fictional writing.

Part Three addresses questions of communication, rhetoric and representation of the scalar experience (we should not forget that the author is professor of English and well trained in rhetoric). Central in this part is of course the problem of the (relative) impossibility to communicate the uniqueness and specificity of such an experience, which raises the double problem of, on the one hand, the limits of representation, in language as well as trough other media, and, on the other hand, the role and status of rhetoric. Here, DiCaglio zooms in on Plato, the allegedly supreme enemy of all things rhetoric. The close-reading of some key fragments of Plato’s work help the author bring to the fore a more nuanced interpretation, which underlines the positive aspects of words and language. The horizon of Scale Theory is however neither scale nor theory. If scale is the object under scrutiny and theory the chosen perspective on that object, DiCaglio’s major concern is unquestionably “mystical”, in the broad and open sense hinted at above. Not in the perhaps somewhat naïve (nonscalar) way of dissolving the boundaries between “I” and the “universe”, but nevertheless with a strong ethical and political call to reconsider our place and role in that universe.