Smellosophy: What the Nose Tells the Mind

Smell is the Cinderella of our senses. It has acquired a remarkably poor reputation throughout history. Traditionally dismissed as communicating merely subjective feelings and brutish sensations, the sense of smell never attracted critical attention in philosophy or science. The French Enlightenment philosopher Étienne Bonnot de Condillac remarked in 1754: “Of all the senses it is the one which appears to contribute least to the cognitions of the human mind.”¹ And Immanuel Kant, philosophical pillar of Prussian precision, judged as follows:

Which organic sense is the most ungrateful and also seems the most dispensable? The sense of smell. It does not pay to cultivate it or to refine it at all in order to enjoy; for there are more disgusting objects than pleasant ones (especially in crowded places), and even when we come across something fragrant, the pleasure coming from the sense of smell is fleeting and transient.²

It remains unclear to me what makes Kant an expert on pleasure. But in addition to philosophers, scientists also showed little regard for the human nose. Charles Darwin noted in 1874 that “the sense of smell is of extremely slight service” to humankind.³ Olfaction lacked reputability for scholarly investment.

Things began to change in the mid-twentieth century. A growing community of researchers recognized the potential of olfaction as a new model for the study of the senses. Revolutionary developments in neuroscience fundamentally opened up possibilities regarding its methods and outlook, especially over the past few decades. Odor perception and its neural basis are becoming key to understanding the mind through the brain. It is time to adjust our somewhat stale philosophical conjectures of mind and brain to these new realities.

This book sets out to do that. It is the book I would have wanted to read when my interest in the nose—and how it communicates with the mind—sparked. There has been a tremendous amount of sophisticated research in olfaction recently. It is time to celebrate that work. Smellosophy is an unapologetic declaration of love to olfaction. It provides an integrated perspective on the various creative strands of research that explore what the nose knows. These strands encompass developments in neuroscience, molecular biology, genetics, chemistry, psychology, cognitive science, and philosophy, as well as expertise in perfumery and winemaking. The philosophical tenor of this book goes beyond interdisciplinary synthesis, however. It presents an outlook, not a summary, and points at new avenues by identifying the open issues in current thinking about smell. This would have been impossible without many experts lending me their time and voice to talk about the field and its development. These conversations revealed just how diverse the field is in terms of disciplines, personalities, and opinions. It was not possible to capture all the voices (sincere apologies to those not covered), and not everyone will necessarily agree with the central argument of this book.

In the end, research on the nose continues to be in flux. Discoveries are going to be made after this publication. Maybe these discoveries will shed new light on the themes in this book, either further strengthening its claims or sounding discordant notes. After all, the book must end where the future of olfaction begins. (Here’s looking at you, kid!)