W. H. Auden once said that we live societies “to which the study of that which can be weighed and measured is a consuming love” – but that hasn’t always been the case. The science of Aristotle, arguably the biggest influence on post-Hellenic science west of the Levant, was thoroughly qualitative. Only later, after the rediscovery of the Plato whose fascination with numbers and ratios bordered on worship, did science begin to take on a properly quantitative quality. As the subtitle of the book hints, this begins to happen sometime in the mid-thirteenth century, and this is precisely the set of stories that Crosby seeks to elucidate for the general reader. He wants to retrace the steps that took us from a world of “emotional attachment to perception and experience, to a visualizing and quantifiable approach to reality,” to “comprehending reality as composed of quanta.”

Because of what Crosby is trying to do, much of the book reads like a survey of medieval and Renaissance math and science. In a few hundred years, the West went from the Dark Ages (I’ve always despised that term since it’s so wrong and inappropriate, but if fits anywhere it’s true of the quantitative sciences) to the bourgeoning of an array of common things and ideas that would have been impossible without better economizers; just a few of these things include military maneuvering, increasing calendrical accuracy (i.e., the transition from the Julian to the Gregorian calendar), cartography, time-keeping devices, grammar and alphabetization, geometric perspective in painting, astronomy and currency and bookkeeping. The invention of polyphonic music, perhaps the greatest innovation of the medieval West, would have been impossible without the modern musical notation that replaced neumatic notation (commonly, though questionably, attributed to Guido of Arezzo during the early eleventh century).

His chapter on the development of music from 600 to around 1500 traces its development from the earliest Gregorian chant to the acme of Flemish polyphony, stating that the importance of music can be traced to its unique place in the quadrivium as “the only one of the four members in which measurement had immediate practical application.” Similarly, as the medieval visual art gently bleeds into the masterpieces of the Renaissance, we see a growing fascination with naturalism in painting that would have been impossible without new insights into optics, illusion, perspective, and depth – all quantifiable and “mathematizable.” Those familiar with the Renaissance greats will readily recognize that Leonardo, Masaccio, and Raphael are just as much about mystical Platonic ratios as they are about older, medieval considerations. Crosby ends his historical journey in a place that conveniently ties up several loose knots that would interest other kinds of historians, including those interested in the development of capitalism and the mercantile economy – namely, the advent of double-entry bookkeeping. While the mechanical clock “enabled them to measure time, double entry bookkeeping enabled them to stop it - on paper, at least.”

While Crosby does little to actually make new discoveries in the fields he considers, he goes far in recasting and repurposing the information he has readily available. It seems incontrovertibly true that his central argument is true. How well does his evidence explain or support this argument? This seems shakier to me. As I noted above, taken as a whole, the book can come across as a history of medieval math, medieval science, medieval astronomy, etc. But his voice is quick-witted and engaging, sometimes even chatty – probably not what you were expecting given the title of the book. And rather than fully “accounting” for the rise of the particular phenomenon he is trying to explain, this book at the very least rediscovers some of the important philosophical fundamentals that undergird his concerns. However, he fails at answering the all-important “why?” Perhaps this question is better-suited to cliometricians and psychohistorians than historians of science. ( )

This book is the author's attempt to understand "the amazing success of European imperialism." Don’t stop reading this, however. Whatever the author's motivation, the book's content and the author's writing style are both largely devoid of political bias. Crosby argues that the transition from the middle ages to the Renaissance was in part driven by a cultural shift toward measurement-based thinking and away from qualitative and intuitive ways of thinking. He argues (by example and at length - the only form of "argument" available to an historian, as Hayek would note)) that the shift was pervasive, and it can be found in arts, commerce and science. The catalyst for all these advances, he avers, was a desire to better manage increased complexity. For example, sending ships to farther destinations required more complex navigation, and hence motivated the development of the mathematics (geometry, specifically) necessary for improved charting. Crosby's alleged rationale for the push toward "panmetry" reminds me of Mises discussion of universal laws of economic behavior (what Mises referred to as laws of "human action"). Specifically, Mises argues that all human action (conscious, willful behavior) is directed at the reduction of discomfort or the increase of comfort. Crosby's arguments would be more compelling if based on Mises reasoning. Crosby's book has many interesting bits of information about the emergence of the measurement culture, and it is worth reading for that. Ultimately, however, Crosby's book fails to make a convincing (or even much of a) case that the widespread adoption of measurement-based thinking was a cause of anything uniquely related to western imperialism. That does not prevent this book from being an interesting read.

Fascinating glimpse inside the Renaissance mind. It is the most enlightening book about the Renaissance that I've ever read, and the minute I finished it, I turned back to the first page and read it again. I don't do that too often! ( )

The author writes that he has been seeking for a reason why western Europe came to dominate the world, and thinks he has found it in the tendency of Europeans to quantify and measure the world. He has a fascinating exposition of several renaissance innovations like perspective and book-keeping that involved ways of quantizing and measuring, and started men thinking about the usefulness of measurement. Algebra and the introduction of arabic numerals also played a role. This is an unusual perspective on the intellectual history of the Renaissance, very readable. ( )

If you can measure it, you can manage it.