Logic, Reason, and Emotion in Biocultural Perspective

Where do we derive our reasons, rationalizations, and explanations from? How do we discover, define, and decide to adopt new concepts? Logical reasoning is part and parcel of our actions and thoughts, in everyday practice, throughout our lives. The problem with human logic is that the very symbolic systems we use to represent our logical arguments inevitably allow us to represent absurd or contradictory arguments, too. Even from the beginning, in learning to use a logical system of representation, we have to get over the fact we’re also learning arbitrary choices of symbols that are set by convention, to refer to certain concepts. So we all too easily forget that when we were young, there was a time–as late as six or seven for many of us (and we still turned out ok)–that “2 + 2 = 4” was gobbledigook nonsense. Logic can lead us into confusion, even before our more complex thoughts really get going.
When we think about logic, we tend to focus on how one can rationally draw conclusions from premises. So we make deductive arguments. In our minds. Orally. Through various literate media: writing, print, electronic. We do so in order to explain our environment, justify courses of action, establish reassurances that the world has some predictable order in it. We tell ourselves and others that certain conditions have necessary implications that we need to expect and be prepared for.
We use inductive logic, too. Perhaps even more often. We have an experience, make an observation about how two phenomena relate … or perhaps how something has changed over time, and we generalize our understanding of why the change occurred. Why phenomenon A implied phenomenon B. We build the relationship between A and B into a general concept.
Hopefully, it’s needless to say that logical thought and communication can aid effective behavior. We have to navigate intricately interrelated social, material, and ecological environments. Some logic is usually better than none. Other things being equal, an animal that can use logic to organize information and guide its course of action will have greater chances for survival and reproductive success than another population member who is only capable of random, unpredictable irrationality.
From a biocultural perspective, then, logical arguments are not just interesting for philosophers, mathematicians, and computer programmers. The capacity to make logical arguments has long been evolving in nature–in the form of embodied cognitive representations. More to the point, the cognitive capacity for logical decision-making has been shaped by natural selection–in a wide range of animals, at least in many birds and mammals–as an adaptation for learning and effective behavioral decision-making in complex, unpredictable environments.
And natural selection has certainly continued to influence the human capacity for constructing and sharing logical arguments. The evolutionary emergence of socially shared logical representations has unfolded over the roughly seven million years since the hominin lineage evolved a reproductive barrier with the chimpanzee-bonobo lineage. Still, there is an important “but” here. Human beings have a greater capacity to focus attention on and construct logical arguments than any other animal species. But …
But most of us care little about the philosophical perspective–that is, about logical arguments about logic itself. And even for those of us who do, we can easily confuse ourselves. Or not even notice where the boundary between logical reason and illogic may lie. In other words, logical understanding and the explanation of logic–either as an abstract representational phenomenon or as a computational or cognitive procedure for making a chain of iterative decisions in the world–is really difficult (Millikan 2000; Sperber & Wilson 1995). Has been for a long time.
My aim in this post is to present a biocultural perspective on logical systems of representation, where one of the most salient features of open logical systems is this: there is a pervasive gray zone between arbitrary, irrational choice that open logical systems support–that is, between functionally equivalent ways of generating formally different representations that refer to the same things–and the rational claims that those alternative representations express.
Logic, Illogic, and the Interface between Them
The philosopher Charles Sanders Peirce (1839–1914) had a brilliant, complex, integrated approach to explaining how we represent the world and our place in it … He’s most definitely not alone among philosophers in investigating how to understand both strict, formal logical systems (like mathematics and computer programming languages) and the more common, pervasive, everyday quasi-logical sociolinguistic systems that we turn into practical but sloppy, complicated, often logically contradictory real-world practical tools.

Where Peirce seems to have a unique legacy is in his parallel influence on cultural anthropology and the humanities, on the one hand, and cognitive science, on the other. Peirce is just as towering an intellectual figure for many cultural anthropologists as he is for researchers on the biological evolution of human cognition. Not that members of both groups get together too often to bond over Peirce. It’s just that it’s a rare and substantial theoretical connection bridging what is arguably the biggest, most antagonistic intellectual divide across all of academic scholarship. This connection is built on Peirce’s theoretical analysis of the way that logical systems of representation are structured–and how they function. In a particularly influential writing, “Logic as Semiotic: The Theory of Signs” (which is actually a collection of manuscripts and brief publications written between 1893 and 1910), Peirce commented on the identity relationship between logic and symbolism (Peirce 2012: Kindle location 1937):
“LOGIC, in its general sense, is, as I believe I have shown, only another name for semiotic.”
Logic is about a system of rules for representation, including rules for inferring the relationships among signs, the objects to which they point or refer in the environment, and the “interpretants”–that is, the embodied mental representations that cognitively mediate the connection between a more abstract symbol and the object. As in: the relationships among the word “cat,” Herschel (our neighborhood cat/rodent controller; see right), and my mental image of Herschel and related cat-thoughts I have when I think, listen, read, or talk about Herschel and the symbolically coded sign “cat.” Logic is about recursively combining and recombining symbolic representations into larger ones, too. So that I can focus on the symbolic relationships among “cat,” a general notion of catness I’ve experienced and thought about, and specific memories or present interactions with Herschel, combining in my mind coherent symbolic thoughts, using deductive logic from inductively learned grammatical rules and lexical symbols, to assemble the sentence: “Herschel is a really awesome cat, and I’m glad he’s adopted us and the neighboring families.” Semiotic involves the complex logical production and interpretation of signs, something that we all do–all the time–as we are impacted by and engaged in our environment.
On a fundamental level, Peirce opened the way for the major Twentieth Century philosophical work of Russell, Wittgenstein, and Gödel, which led to difficult–but thoroughly deductively reasoned and inductively supported–claims that rule-based (axiomatic) systems of representation may be surprisingly imprecise … or, to take Gödel’s Incompleteness Theorems as a critical example, that even seemingly simple logical representation systems in mathematics inevitably harbor some logically inconsistent shadowy corners. Later, the richness of Peirce’s framework for explaining signs we use to create and interpret meaning helped to open the way for semiotic approaches in cultural anthropology and the humanities. The intensity of interpretation, the dynamic nature of symbolic construction in social practice, and the potential for semiotic systems to produce multiple meanings or intricately, subtly evocatively interrelated meanings–these are all central aspects of lifelong human social experience, with the resulting symbolic and material worlds we create.
So, we have the cognitive science side of Peirce’s intellectual legacy still largely concerned with the fundamentals of logic and communication (e.g., Sperber & Wilson 1995). And we have cultural anthropology and the humanities (including many highly influential Continental philosophers) interested in how complex webs of signs shape and constrain our thoughts and actions in a larger political field of power relations. The former perspective is–quite reasonably–tethered to the importance of logic. The latter perspective is firmly entrenched in the illogical or pseudological constructions–that is, the inconsistently absurd or contradictory juxtapositions among signs–that we so frequently experience in our social lives and easily produce in our socially engaged imaginations. In fact, illogical constructions are so pervasive in human life that it is easy to overlook the logical foundations of the symbolic systems through which we generate and are emotionally affected by representations. And as is so often the case in academic inquiry across a range of fields, communities of scholars focusing on one scale of a complex phenomenon reify what is really a traversable distance to another scale of that phenomenon. This distance is made into an actively, mutually monitored academic territorial boundary. Logic, cognition, and communication on one side and structure, ideology, and power on the other. Efforts to bridge this chasm–or better yet, simply reveal that the chasm is actually a lovely valley where both sides would get a better perspective on their problems–tend not to get widely read or seriously discussed by their respective sides.
One could argue (take it ironically or not) that the fact of this socially constructed chasm between arguably overlapping scholarly fields of inquiry provides support for Peirce’s pragmatic philosophical view of how systems of signs influence us…
I really hope that the simple fact that logic and illogic constantly work side by side in our embodied cognitive actions and experiences leads more of us to acknowledge, well, that we should integrate investigations, analyses, and discussions that have remained academically quite separate. We have not recognized how the interface–and a very emotional, dynamically embodied and social interface, at that–between the logical and illogical helps us to understand the biocultural foundations of human cognition and the systemic emergence of characteristically human, highly complex ideological political structures.
The Arbitrary Foundations of Logical Systems of Representation
It’s worth taking a step back and reconsidering the logical foundations of human illogic. Here, it should be blatantly apparent how integral non-logical decisions are to fundamentally logical systems of representation.
Logical reasoning depends on the system of thought we’re using–or even more basically, the system of information processing–having a sufficiently consistent and complete set of rules of representation. These rules do not have to be deduced from prior principles. Although the rules have to have some level of consistent logic in terms of how those rules get selectively or recursively combined to achieve intended (and sometimes unintended) representations, they are surprisingly arbitrary. Thus, a logical system for representing real numbers–stretching from negative to positive infinity, including zero, and encompassing any fraction between two integers, including irrational numbers like Π (pi)–will have arbitrary symbols for zero and the basic digits; rules for combining those symbols with symbols indicating infinity, positive, negative, fractions of integers; and a set of rules for combining the zero and basic digit symbols into larger numbers or more finely resolved fractions. Such a system is open-ended, albeit fully logically consistent. The incorporation of the infinite and infinitesimal allows us to deduce logically that there are an infinite quantity of real numbers that exist but that none of us will ever encounter in mathematical investigations or real-world measurements. But with sufficient resources and time, a computer (or superhuman) could use the logical system to name at least one arbitrarily large or small number that has never been named before. The thing is, once we get into the groove of thinking about such cosmic deductions–which are triply abstract in the sense that they, themselves, are symbolic representations about symbolic representations that also represent facts that are logically deduced but that will never be encountered in any human interaction with the world around us–we can very very easily lose sight of the arbitrary foundation of the logical system.

Indeed, a committed but eccentric mathematician might define multiple private systems of symbols for basic digits including zero, positive and negative values, fractions, and infinity. Moreover, that mathematician will almost certainly play with different bases for combining those other symbols into larger or smaller positive or negative values. Already, computer engineers over the past 70 or 80 years have learned to translate between base-ten and binary systems for representing the same objective quantities. And although detailed human concern about logically representing really big or tiny quantities is relatively recent, any reader who also knows Arabic or Hindi will have learned a slightly different set of symbols for the basic digits in the base-ten system. The Roman numeral system for using the letters I, V, X, L, C, D, and M with rules for combining them is easily learned, but it is also clearly arbitrary. It allows one to count positive integers into the thousands, but each positive integer quantity coded by a unique sequence of I’s, V’s, X’s, L’s, C’s, D’s, and M’s can also be represented by one unique sequence of one, two, three, or four base-ten digits: I = 1, II = 2 … DCCXLIX = 749 … MMMCCLIX = 3259 … Some non-literate traditional societies have linguistic symbols and rules for combining the basic digits on a base 20 system for counting positive integers (Mimica 1988). Here, the seemingly natural Indo-Arabic tradition of base-ten counting on the fingers turns out to have been an arbitrary cultural choice–a choice not to include the toes … just the fingers.
We could create pretty much any complete system for representing positive integers or even–more comprehensively–real numbers. Although some systems might seem strange or irrational to an outsider, all such systems are learnable by humans. And once learned, they help us equally well count sheep, carry out arithmetic calculations, or measure the volume of gasoline we just added to our car’s tank.
To be sure, there’s a rational reason to use a binary (or base two) symbolic system in electronic computers. There’s nothing analog about electronic circuits. They are either on or off. It’s just digital. Yet, each auditory symbol representing a basic digit is a continuous analog phonological pattern: “seven,” for instance. A corresponding visual symbol is a continuous analog pattern in two dimensions: “7.” We can take different analog-structured symbols and juxtapose them, achieving a digital contrast between two or more ordered analog patterns–“seven” versus “eight” and “7” versus “8”–are clearly much more complex than the simple electronic on-off binary distinction. And it is here, in the analog form of basic symbols, that the rules for their definition and combinations may be very arbitrary. There is no rational reason to choose one visual or auditory symbolic system over another when people count or do arithmetic. It’s just that we usually don’t see this as a choice, because we learn early in life just one or two systems that are already common in our social environment.
ANALOG AND DIGITAL TOGETHER:
Arbitrary Use of Analog Symbols and Logical–but Arbitrary–Rules Defining the Digital Contrasts Between Them
What we learn to speak, hear, write, type, engrave, and see are hybrid analog-digital systems. In general, this hybrid structure increases the dimensionality of information conveyed in human symbolic auditory and visual messages. In turn, this allows for variation in expression, handwriting, or typeface, adding to the information that receivers (listeners and readers, that is) must handle from various transmitters (speakers, actors, authors). And this requires the receiver to move hierarchically between nested patterns of distinction–between more or less clearly perceived articulated phonemes that constitute words, between more or less clearly perceived articulated words in the message, and the overall–presumably properly logically, grammatically coded–message. This strikingly rapid, complex interpretive process is a learned cognitive one. The interpreter mentally interpolates between points of confusion and clarity, reaching a logical, recursively and jointly deductive (applying previously inductively discovered, basic culturally acquired phonological, lexical, and grammatical rules) and inductive (based on more recent prior experience in discourse) conclusion about the most likely correct, sensible interpretation.
Now, linguists and anthropologists usually emphasize the multilevel arbitrariness of any given cultural symbolic system that supports a human language community. Natural languages and dialects vary widely in the range of vowel and consonant phonemes that constitute socially acceptable sounds and combinations of sounds that may be incorporated into those analog auditory patterns that are arbitrarily–by social convention and tradition–taken as codes to refer to things, actions, ideas, states of being, and relationships. That is, the analog auditory symbol that refers to dogs in English is arbitrary. “Dog” bears no resemblance phonologically to “chien,” “perro,” or “hund” (the French, Spanish, and Swedish words, respectively, referring to members of the same ontological fuzzy set {dogs}). But more than that, even if the English word for dog had an “r” sound in it, the Spanish rolled “r”–with its complex anterior palatal/superior dental articulation–does not exist in English. Linguistic symbolic codes have to have a substantial set of consistent implicit rules to balance having sufficient phonemic and lexical variation to produce large numbers of contrasting sound patterns with not having so much variation that language community members can depend on being able to understand one another. It’s worth noting that even if it became popular in English to systematically replace the commonly used word “dog” with the word “canine”–making the English version etymologically parallel to the French word, with both culturally descending from the older Latin “canis”–the almost guttural and non-palatal French “n” is phonologically near but nonetheless distinct from the related, anterior palatal English “n.” The nested hierarchically organized structure of human language involves double articulation, also known as duality of patterning (Hockett 1961). Here, contrasting phonological elements are ordered to build lexical items, which in turn offer contrasting symbolic patterns that can be articulated grammatically to make more complex utterances in thought and discourse. Even on the grammatical level, the rules for representing subject-verb-object relationships, verb tense and voice, preposition-prepositional object relationships, etc., can vary. As with logical systems for representing real numbers or positive integers, the more complex cultural-linguistic systems involving the hierarchical articulation of phonological contrasts to lexical contrasts, yielding emergent grammatically ordered messages, are not willy-nilly arbitrary. Just as a base-67 counting system with rare, long sequences of tonal distinctions representing infinity, fractions, negative, and positive would be difficult to learn and cumbersome to use in everyday life, we would also expect practical limits on phoneme number and distinctions, certain phoneme articulations that are anatomically relatively difficult for the mouth to quickly produce, lexicon size, and grammatical complexity. It is likely that cultural processes of social identity distinction and boundary production can historically favor linguistic divergence or increase in linguistic complexity. But what is striking is the cultural diversity that these social processes have generated among extant languages and dialects. Variation in the logical basis of symbolic representation among human communities exhibits an enormous amount of arbitrariness.
Back to Logical Arguments:
It’s Not Just the Arbitrariness of Symbolic Representation Systems …
O.K. We have to acknowledge that this arbitrariness, at the basic level of representational rules, is really important for modern linguistics and sociocultural anthropology. The fact that symbolic arbitrariness is a big, weird, difficult-to-grasp, but inescapable part of our social life and imagination–well, it functions for anthropologists somewhere between theoretically justified intellectual touchstone and entirely irrationally held security blanket. The arbitrariness of social–mainly linguistic–symbols comprises a major empirical pillar on which anthropologists have achieved a quite profound appreciation of humanity’s extraordinary linguistic and cultural diversity. But anthropology’s theoretical focus on the arbitrariness of symbolic representations has taken up our attention too successfully, too thoroughly (Gell 1999). We have rarely paused to look up and investigate how it actually works for our surprisingly arbitrary representational systems to support more complex logical explanations, assertions, inferences, and decisions.
So let’s pause and look around the logical representation systems landscape.
It is a trivial observation to note that there’s more to the basic human logical capacity for thought and communication than just symbolic representation in general.

Another way of saying it: it is worth repeating that we learn and use arbitrary logical systems based on arbitrary, non-logical choices about how we make relevant representations. We may say “dog” … or we may say “perro”–depending on linguistic context–to point toward or evoke the same concept dog, a concept that is relevant for helping us deal with similar aspects of real-world environments that are sometimes encountered by Spanish and English speakers, alike. And to be sure, our logical systems of symbolic representation do not necessarily, consistently produce more complex logical representations, such as those that involve a deductive or inductive chain of reasoning. So although we might socially share a logical set of rules that involve defining “perro” as referring to a dog-ish concept in Spanish, the conscious verbal thought or utterance, “¡Perro!” itself does not refer to or represent a larger logical concept. The speaker or thinker might have seen a dog she’d never met, might have remembered something about a dog, might be insulting someone. A non-native Spanish speaker might simply be using the word “perro” to practice rolling or trilling the “r” consonant. The discipline of Anthropology has long emphasized just how extensively irrational–or simply arational–our symbolic representations are. We come to use symbols to refer to non-logical thoughts and utterances all the time (ranging from a thoroughly ambiguous representation constituted by the simple utterance, “¡Perro!” to a clear statement of observation made with a further disambiguating pointing gesture, “¡Mira! ¡Es un perro!”). And usually, this is where anthropologists leave things.
It’s here that we need to recognize that there’s an another important “but” that we need to consider.
So here it is:
But we also use logical but arbitrary representational systems to recursively generate more complex representations that refer to logical relationships of implication… As in, “¡Mira! El perro es lloriqueo. Probablemente tiene que salir.” (Look! The dog is whining. It probably has to go out, at least according to Google Translator.) In fact, we construct, interpret, and express logical implication-relation representations all the time. These are useful in rationalizing, hypothesizing, estimating, explaining–whether on the personal level of how to feed your family or whom to marry … or on the general theoretical level of cosmological foundations for morality, physics, or aesthetics. Thus, the logical and illogical are constantly enmeshed across a non-nested hierarchically structured process of representation construction.
How Does Living with Logic and Illogic Make You Feel?
But (quite logically) this complicated, arbitrary, irrational feature of naturally evolved and evolving open symbolic systems has a biocultural implication. We cannot understand the evolution of our capacity for logical argument without also understanding the systemic role of feeling and emotional reaction in the mentally iterative or socially discursive construction of logically generated symbolic representations. Consider that:
- It is reasonable to expect that we may feel anxious, alarmed, or scared when we face a serious obstacle or threat to our well-being. Falling ill, being in a precarious physical situation or even getting injured, losing a loved one, getting lost, facing food insecurity, or interpersonal/intergroup violence.
- It is also reasonable to expect that we’ll have similar feelings we face a social conflict of interest, and indeed, our feelings and emotional experiences may be more intense if conflicts of interest involve threats of violence.
- It is further reasonable to expect a range of other feelings and emotions that we will go through afterward, assuming we survive such threats. Satisfaction, relief, regret, pride, elation. It depends on exactly what happened, to be sure, along with our narrative sense of the past.
- We face more minor challenges symbolically all the time, confronted with a non-nested hierarchically structured, incompletely predictable pattern of non-logical sign relationships. And facing and overcoming symbolic arbitrary choices, absurdities, and contradictions also symbolically resembles–that is, stands in metaphorical relation to–facing and surviving (overcoming or recovering from) physical challenges and social conflicts.
- In order to engage in our highly social lives, we face and survive symbolic arbitrary choices, absurdities, and contradictions throughout our waking experience … and it’s safe to say that we dream about such symbolic challenges, too.
- Therefore, our capacity for logical representation entails a constant embodied emotional engagement with logic and its limits.
The emotional interface between logic and illogic has likely shaped and been shaped by our biological evolution in a profound way. This has hardly been recognized by anthropologists or philosophers. But I would suggest that this surprising but relatively simple insight is necessary for sufficiently understanding the evolution of our emotional engagement in extraordinarily complex symbolic worlds that come to constitute our quite complicated and often dangerous socially intense terrestrial and heterotrophic niche.
References
Hockett, C. F. (1961). Linguistic Elements and Their Relations. Language, 37(1), 29–53. doi:10.2307/411248
Millikan, R. G. (2000). On Clear and Confused Ideas: An Essay about Substance Concepts. Cambridge University Press.
Mimica, J. (1988). Intimations of Infinity: The Cultural Meanings of the Iqwaye Counting and Number Systems. Berg Publishers.
Sperber, D., & Wilson, D. (1995). Relevance: Communication and Cognition (2nd ed.). Wiley.
Peirce, Charles S. (2012). Logic as Semiotic: The Theory of Signs. In Philosophical Writings of Peirce (Kindle Locations 1937-1938). Dover Publications. Kindle Edition.