The Scented World
It has been said that chemical signals were the earliest signals exchanged between organisms, and that our sense of smell is what remains of our exchange of chemical signals from our distant and most rudimentary ancestors. And we know that our sense of smell is not particularly keen, since our dogs, possibly the species that is closest to us emotionally and socially (though not genetically), and with which we spend so much time, possess far greater acuity than we do in this respect. We use the noses of dogs as a proxy for our own, feeble noses, extending our senses not through augmentation or instrumentation, but through cooperation.
It could be worse for us, in terms of our sense of smell. Cetaceans were thought to have entirely sacrificed their sense of smell to the evolutionary process of re-adapting to an aquatic life (cf. How Dolphins Lost their Sense of Smell by Stephen J. Godfrey), though recent research has shown that some whales (baleen whales) do, after all, have some remaining sense of smell (cf. Aquatic adaptation and the evolution of smell and taste in whales, by Takushi Kishida, J. G. M. Thewissen, Takashi Hayakawa, Hiroo Imai, and Kiyokazu Agata). Loss or diminution of sense of smell has entailed particular evolutionary adaptations (cf. Somatosensation, Echolocation, and Underwater Sniffing: Adaptations Allow Mammals Without Traditional Olfactory Capabilities to Forage for Food Underwater by Sarah Marriott, Emily Cowan, Jacob Cohen, and Robert M Hallock), and we may wonder what subtle adaptations we have made to the feebleness of our noses.
The canine nose is more complex than our hominid noses, and the canine brain devotes more resources to processing scents than our brain does. A dog is primarily an olfactory being, in the way that we are primarily visual beings. Dogs also hear better than we do, and it has been this sensory complementarity that has made the relationship between human beings and dogs so effective — and so long lasting. We are their eyes, and they are our noses and ears.
I have often referenced the Thomas Nagel essay “What is it Like to Be a Bat?” (in Mortal Questions, Cambridge University Press, 1979; I have discussed this essay in, e.g., What is it like to be a serpent?). Bats are an interesting case because of the prominent role that echolocation plays in their experience, and, given that there is something that it is like to be a bat, what it is like to be a bat is likely constructed around the centrality of auditory experience. Dogs are a similarly interesting case because of the prominent role that olfaction plays in their experience, and we would expect canine experience is constructed around the centrality of olfactory experience, as human experience is largely constructed around the centrality of visual experience.
But while the human ability to smell is marginal compared to dogs, it can still play a significant role in our experience. The other day I was struck by the sequence of vivid scents that I encountered. I live on the Columbia River, and while some days the smell of the river is barely noticeable, when it is present, it is unmistakable — like being at the coast and smelling the unmistakable depth and complexity of the ocean air. The river is a smell of living water, like the ocean, but different. Absent is the salt air smell, and present in the smell of the muddy bank of the river, and all these presences and absences are mixed up with each other in a way that human language cannot convey, probably because human language is constructed around the centrality of visual experience, and our conceptual framework and vocabulary for olfactory experiences are impoverished.
Another example of the subtle mixtures of smells that came to mind when I thought of ocean in contrast to river smells is the difference between wood smoke from a fire built for heating and wood smoke from a fire that is used for cooking. Obviously, smoke mixed with cooking smells like food, and we are keenly orientated toward food as a survival instinct, but it is more than this, though what exactly makes it different I cannot say. Scents in this way exhibit the kind of complexity that we hear in spoken language, and which I attempted to describe in The Human Overview, though we are more able to parse the subtleties of language and its usage than scents and how they linger.
In any case, the other morning when the smell of the river came to me vividly, not long after I drove to work, and, as it was a nice day, I had the window wide open. I drove through a smell that I instantly recognized (if that is the right word for it) as one of the “good” smells of an industrialized city — like the cookie factory not far from my house, which makes the entire neighborhood smell like a bakery when the wind is blowing in the right direction, only in this case I knew it wasn’t the cookie factory — not long after followed by some of the “bad” smells of an industrialized city — the pungent odor of grease, oil, and other petrochemicals. There is also the smell of the city itself, apart from the odors of industrialization, and there is a generic city smell, and a smell peculiar to each city.
My day of vivid odors made me think of my recent post The Audible Universe, which I had written explicitly to contrast with the familiar idea of the visible universe with the idea of the audible universe. This project could be expanded to all five of the canonical senses recognized in Aristotle’s On the Soul, so that we might distinguish the visible universe, the audible universe, the scented universe, the tasted universe, and the tactile universe. Of course, we know that this canonical Aristotelian division of the senses is inadequate, and today we recognize “raw feels” such as are experienced as kinesthetic sensations and proprioception, and we know that other species not only have sensory organs that are sharper or duller than our own, but also entirely distinct senses, like the shark’s ability to sense electricity (electroreception) and a pit viper’s ability to sense infrared (cf. The Future of the Pit Viper).
We could add these varieties of raw feels to our catalog of observed worlds and speak, for example, of the kinesthetic universe, though just as we know that the traditional schematization of the senses is inadequate, so too we know that any single one of these perspectives on the world — visible, audible, or scented, etc. — is abstract when taken in isolation from the totality of experience in which it plays a role. That our knowledge of astronomy until relatively recently was entirely a matter of the visible universe probably has accounted for how we have conceived of the cosmos, whereas our conception of the night, in which we cannot see, so that we often conceive it in auditory terms — things that go bump in the night, as tradition would have it — is probably shaped by our relationship to hearing, which is different from our relationship to sight.
While the scented world is, for us, often attenuated to the point of irrelevance, its intensity is, at times, overwhelming, as it was for me the other morning. And even when the scented world is not vivid, but is only in the background, perceived only at a subconscious level, it probably affects us more than we realize. Perhaps smell is one of the factors that most decisively differentiates lived experience from experience that has been rendered as scientific knowledge, because what we smell vividly affects us so deeply (as is to be expected from this remnant of the most primitive chemical signaling among organisms), dredging up memories and feelings long past, perhaps even suppressed, while the preconscious or unconscious experience of the background smells that constitute our world would be missed if they were not there, but are not noticed to be absent in formalized account of knowledge. The totality of experience in lived experience could be symbolically represented by the scented world, which reveals the formalization of experience in scientific knowledge as something less than totality of knowledge.