In the 16th century Nicolaus Copernicus changed the course of scientific inquiry by proposing that Earth orbits the Sun and not the other way around. Contrary to the prevailing opinion of the time, he argued that Earth is not special, not privileged, not the center of the universe. Thus began centuries of scientific progress in which it became ever more clear that very little about our planet or our species is special. Scientists learned that when there are competing theories—one assuming humans are special and one assuming we aren’t—the smart bet is on the not-so-special. After the mathematician who started it all, this long-term inclination from the special toward the not-so-special in scientific thinking is called the Coperitican Principle.
“The Copernican Revolution taught us that it was a mistake to assume, without sufficient reason, that we occupy a privileged position in the Universe,” writes astrophysicist J. Richard Gott. “Darwin showed that, in terms of origin, we are not privileged above other species. Our position around an ordinary star in an ordinary galaxy in an ordinary supercluster continues to look less and less special.”s The discovery of thousands of exoplanets makes it increasingly unlikely that Earth is all that special in its ability to support life.
Many scholars have long thought that language makes humans special, that speech is the distinguishing characteristic of our species. To this end, researchers, including Steven Pinker and Noam Chomsky, have prepared inventories of the properties of speech versus other animal communication systems to ascertain what is special about human language. Chomsky and linguist Robert Berwick even named their book about language evolution the decidedly un- Copernican Why Only Us?4 So far, their question remains unanswered; there is no consensus on what is special about the special.10
My view is unabashedly Copernican: human language is neither special nor privileged. However, I do not come to this view by comparing human speech to birdsong, monkey calls, or bee dances. The not-so-specialness of our language is not revealed by comparing human speech with animal communication. But this is not to say that we are no more than social primates, or that speech has no unique features to distinguish it from other animal communication systems.
Rather, I think human language is not-so-special precisely because it is a system of sequences, and in that it is not alone. We know of at least one other system of sequences with equivalent properties, the DNA-based genetic system that underpins life. Human language is not a different thing; it is a second example of a more general kind of thing. And when there are two examples of something, it becomes difficult to argue that one is more special than the other. Thus, the Copernican Principle can plant its flag in new territory.
So, what about all of those exoplanets? How many are barren, like the early Earth? How many of them harbor something that we would recognize as life? Why would we conclude that a collection of matter on a distant planet is a living system rather than just some arbitrary arrangement of complex dynamics? For astrobiologists, this is a scientific question, for humanity perhaps an existential concern.
Answers are hard to come by; there is no general definition of life because, it is thought, we have only one example to work with. As Kim Sterelny and philosopher Paul Griffiths ask, how can we possibly distinguish “between accidental and essential features of life with a sample size of one?”11 This is called the N = 1 Problem. “Thus far, we know only one example of a planet that bears life: Earth,” writes astrobiologist Douglas Vakoch. “Consequently, we search for life beyond Earth by drawing analogies to ‘life as we know it.’”12
Agreed, N = 1 is a problem. However, N = 2 is less of a problem, and the central conclusion of this book is that our sample size is twice as big as researchers have thought. Earth has evolved not just one system of sequences, the living world but also a second—literate civilization—that piggybacks on the first. We still have no idea about the odds of a given planet crossing von Neumann’s threshold even once, much less twice, but it is increasingly hard to imagine such a crossing happening without sequences, one-dimensional patterns that actually get control of physical systems.
- 1. Pattee 1982b
- 2. Lovelace 1843
- 3. This continuum offers a framework for describing the diverging world views of Gunther Stent’s structurisls and iirformationists in molecular biology, as endnoted in the Introduction (1968). Broadly speaking, the structurists view the continuum from its left end, the pole of physics. The informationists view it from its right end, the pole of computation.
- 4. Tomasello 2008
- 5. Pattee 1969
- 6. Vygotsky 1962
- 7. Woese 2002
- 8. Gott 1993; See also Barash 2018.
- 9. Berwick & Chomsky 2016. See also Moore 2017 and Gong et al. 2018.
- 10. One important dispute centers on whether speech depends on something special about the human brain or whether it relies on more general properties of cognition and social intelligence. Without getting into the details, the Copernican Principle alone would point away from the special and toward the general (Hauser et al. 2002; Pinker & JackendofT 2005; Fitch et al. 2005; Jackendoff & Pinker 2005; Christiansen & Chater 2016).
- 11. Sterelny & Griffiths 1999
- 12. Vakoch 2013