Recently, my fellow blogger David Henderson shared some intriguing thoughts on the boundaries of self-ownership. He posited that the government should refrain from imposing restrictions on the self-ownership of mentally sound adults, yet it may be justifiable to impose such limits on children and individuals deemed mentally unfit. This raises a compelling question: how do we ascertain when a child transitions into adulthood, and what criteria define mental soundness in adults?
One could argue that public policy can establish clear and concrete definitions: anyone over the age of 18 is considered an adult, while those younger are deemed children. Likewise, an IQ score above 85 might classify someone as mentally sound, whereas a score below that thresholds them into the realm of unsoundness. This method certainly appears tidy and straightforward. However, as David aptly points out, it comes with two significant challenges.
The first challenge lies in the inherent arbitrariness of drawing a strict line at any specific threshold. Take IQ, for instance: the difference between an individual with an IQ of 85 and one with an IQ of 84 is negligible in everyday life. Yet, the former is categorized as mentally sound while the latter is not, despite their similar capabilities. Similarly, consider a 17-year-old on the eve of their 18th birthday; when the clock strikes midnight, they suddenly find themselves classified as an adult, with the potential for significant legal implications hinging on that minute change.
The second challenge is the inevitable misclassification of individuals on either side of the established line. There are individuals with IQs below 80 who, despite lacking intellectual prowess, demonstrate sound judgment and decision-making capabilities. Conversely, some individuals with IQs soaring above 180 may engage in erratic and irrational behavior. Furthermore, I’ve encountered teenagers who exhibited more maturity and insight at 16 than some adults at 26.
So, how do we address these complexities when attempting to establish limits? If you were expecting a definitive solution from me, I must disappoint you. However, I was reminded of a fascinating insight from Daniel Dennett’s book Intuition Pumps and Other Tools for Thinking, which sheds light on how we often get entangled in such dilemmas.
Dennett begins with a thought-provoking argument suggesting that mammals, in fact, do not exist, based on two seemingly plausible premises:
- Every mammal has a mammal for a mother.
- If any mammals have existed, there has been a finite number of them.
- Therefore, if at least one mammal existed, it follows from the first premise that there must be an infinite number of mammals, which contradicts the second premise. Thus, mammals cannot exist—an inherent contradiction.
Of course, Dennett isn’t genuinely asserting that mammals do not exist. Instead, he employs a Moorean shift, arguing that the conclusion is so absurd that we must reconsider the premises or the reasoning behind them. Thus, we view this argument as a challenge to identify the fallacy lurking within it.
One common response is to challenge the first premise. Along the evolutionary continuum, there were precursors to modern mammals known as therapsids—creatures that were neither fully reptiles nor true mammals. Dennett suggests we could conceptually identify the moment the first “Prime Mammal” was born, thereby disproving the first premise and affirming the existence of mammals. Hooray for evolution!
Yet, things aren’t so straightforward. Let’s imagine we could peer back through time to witness the birth of this Prime Mammal. How would we recognize it? What defining traits would set it apart from its therapsid progenitors? Herein lies the problem of arbitrariness: we might decide to establish ten criteria that define a mammal, and declare the first animal that meets all ten as the Prime Mammal. But why ten? Why not eight or twelve? And why that specific set of ten criteria? As we traverse the evolutionary tree, we’d encounter numerous instances where a mammal with those ten traits mated with a therapsid possessing only nine traits, producing offspring that blur the lines even further.
Dennett proposes a solution that might irk many philosophers: we should embrace the ambiguity and refrain from fixating on drawing rigid lines:
What should we do? We should quell our desire to draw lines. We can accept the unremarkable reality that gradual changes have accumulated over millions of years, resulting in undeniable mammals. Similarly, distinctions between lakes, ponds, and marshes don’t require precise calibration, even from limnologists (those who study inland waters).
This perspective runs counter to the tendencies of philosophers, who often seek neat definitions and precise classifications. Since Socrates incessantly demanded clarity on the essence of virtue, philosophers have been driven to identify definitive characteristics that halt such infinite regressions, seeking the “Prime Mammal” in other contexts too. Thus, as a general guideline, we should consider avoiding the philosophical compulsion for an essence, a defining feature, or a “truth-maker.” These pursuits often lead to wild goose chases—diverting but not particularly enlightening.
The takeaway here is that the very act of setting limits is an endeavor fraught with limitations. We need not fret over our inability to delineate exact boundaries that account for every nuance, as that task is, by its nature, impossible. (As a mathematician once quipped, proving a false theorem is a notoriously challenging feat!) While there are scenarios where strict line-drawing is unavoidable—such as in legal contexts—any lines we do draw must be recognized as imperfect, likely to produce misclassifications. This may be yet another reason to incorporate flexibility into our rules, allowing for exceptions when warranted.
However, we must also avoid the opposite pitfall: the assumption that the absence of an objectively correct, non-arbitrary line renders distinctions meaningless. Matt Zwolinski illustrated this error when he noted how some people leap from acknowledging that property rights require social conventions (which are inherently arbitrary regarding specifics) to the flawed conclusion that the entire concept of property rights is arbitrary and solely dictated by social norms.
In Zwolinski’s words:
One way to circumvent the philosophical puzzles involved in these issues is to simply stipulate an answer through established conventions. The Homestead Act of 1862, for instance, allowed families to claim up to 160 acres of land after residing on it for five years. Why 160 acres and not 180? Why five years instead of three? Clearly, these figures are not dictated by any universal theory of natural rights.
Does this render theories of natural rights useless? Certainly not. Such theories provide overarching principles that delineate a range of morally acceptable solutions to appropriation issues. Societies are free to choose within that range, but the flexibility is not boundless. Whether families claim 160 or 180 acres is less critical than ensuring they cannot seize land already occupied by others.
So, what does all of this imply? While there may not be a singular, definitive set of rules and institutions constituting a “free market,” neither natural law nor economic theory can prescribe the exact nature of a libertarian utopia. Nonetheless, this does not imply that anything goes. It may be impossible to specify precisely where blueish-green shifts into greenish-blue, or when a child becomes an adult, or where a free market ceases to be free. But only someone blinded by philosophical conundrums would conclude that there is no difference between green and blue, a child and an adult, or capitalism and socialism.
The same applies to those who claim there is no distinction between a mammal and a reptile. We may not be able to draw an exact line with mathematical precision, but we can identify a point within the grey area, draw a line, and declare, “that’s good enough.” In many aspects of life, “good enough” is often the most pragmatic approach we can take.
