Is water H2O?

One of the most basic assumptions about water is that it is H2O. The assumption finds its way into all sorts of debates. Critiques of our supposedly scientific culture often bemoan management practices that treat water as only H2O and which fail to incorporate other ways of knowing water (i.e. non-scientific ones). Philosophers have used H2O in debates about essentialism – over whether water is essentially constituted in a certain way and, if so, what that might tell us about “essences” more generally.

It’s all premised on a simple idea, but one that has a really fascinating history and philosophy of its own.

And so, if you haven’t yet come across Hasok Chang’s Is Water H2O: evidence, realism and pluralism, may I recommend that you do. It is too pricey to recommend purchasing, but if you can snag a library copy you will be treated to an in-depth analysis of the ways that theory and practice evolved in the 19th century.

Here is the editor’s description:

“This book exhibits deep philosophical quandaries and intricacies of the historical development of science lying behind a simple and fundamental item of common sense in modern science, namely the composition of water as H₂O. Three main phases of development are critically re-examined, covering the historical period from the 1760s to the 1860s: the Chemical Revolution (through which water first became recognized as a compound, not an element), early electrochemistry (by which water’s compound nature was confirmed), and early atomic chemistry (in which water started out as HO and became H₂O). In each case, the author concludes that the empirical evidence available at the time was not decisive in settling the central debates, and therefore the consensus that was reached was unjustified, or at least premature. This leads to a significant re-examination of the realism question in the philosophy of science, and a unique new advocacy for pluralism in science. Each chapter contains three layers, allowing readers to follow various parts of the book at their chosen level of depth and detail. The second major study in “complementary science”, this book offers a rare combination of philosophy, history and science in a bid to improve scientific knowledge through history and philosophy of science.”