The End of the Machine Metaphor?

Features of life at the cellular level have often been compared to machines. Science writer Philip Ball’s recent book, How Life Works: A User’s Guide to the New Biology (2023), cautions us about such metaphors. Some have argued that machine terminology is inappropriate, as our understanding of machines as designed objects could inadvertently support a design inference for biological systems. And that would be dangerous. Interestingly, Ball offers a completely different reason for moving away from the language of machines. His argument is rooted in the inadequacy of machine terms themselves. He suggests that machine analogies fail to do justice to the extraordinary complexity of biological systems. In his view, describing cells as “machines” risks conveying an inadequate image of the dazzling complexity of the cell. He writes, “Comparing life to a machine, robot, or computer sells it short.” 

Yet, while machine comparisons might oversimplify biology, they also convey critical concepts about the designed nature of biology — insights that help understand and explain living systems.

Philip Ball’s major reason for critiquing the machine metaphor is its limited capacity to convey concepts of meaning and purpose, which he agrees are defining features of life. Notably, in this way his book aligns with a long-standing prediction of intelligent design: that life possesses inherent meaning and purpose (Meyer 2004, O’Leary 2023). But there is sharp disagreement on where these come from, since according to Ball, meaning and purpose are the result of natural selection, a viewpoint that sharply contrasts with the ID perspective.

Can Meaning and Purpose Emerge from Natural Selection?

A common evolutionary explanation for the origin of religion is “group selection.” Writing in the volume Science and Faith in Dialogue, Casey Luskin explains why this doesn’t work:

Explaining the origin of religion has thus also been a major challenge for evo psych. A popular explanation is group selection, where shared religious beliefs helped fostered group cohesion that aided in survival (see e.g. Harari 2015, p. 24). But does that really account for the essence or totality of religion by reducing it to group cooperation? How does group cooperation explain total religious devotion to a deity? When young men or women enter monasteries or convents to pray and serve others, they sacrifice their reproductive success. Why would such sacred religious practices arise in an evolutionary world? Or consider the religious ascetic who willingly dies at the hands of his worst enemies, believing that his own death will save them. Under an evolutionary view, he became a dead end, yet we hold his actions in the highest regard. How do those behaviours help you ‘pass on your genes’? Evo psych explanations of religion fail to capture the totality of the religious experience and struggle to explain many religious beliefs and behaviours that are strikingly non-adaptive.

Relationships with the opposite sex have obvious ties to survival and reproduction. But relationships that many would argue bring the most meaning, namely monogamous relationships, do not necessarily produce the most offspring. And without doubt one can have a deeply meaningful relationship without offspring.

Relationships with animals provide no evident survival or reproductive benefit for the human or animal species, and yet they still convey meaning. Think of the old lady and her chihuahua. If we’re to believe the many videos circulating online, humans can even have friendships with animals well beyond the usual domesticated species — including some surprising ones, such as otters, foxes, even bears (not recommended). Many people and animals risk their own lives for their relationships with others, finding in these acts profound meaning and purpose (at least in the case of humans, I don’t know how animals experience it). Think of the person rushing into a burning house to save a beloved cat, or the dog leaping into flood waters to save the drowning child. Again, this selflessness seems to run counter to the evolutionary premise that prioritizing one’s survival and reproduction is paramount. Instead, it suggests a deeper dimension to meaning that doesn’t align neatly with evolutionary goals. Again, Casey Luskin explains that self-sacrifice is very difficult to explain in evolutionary terms:

Specifically, Darwinian evolution has no basis to account for extreme acts of human kindness. Most people who stumble across strangers trapped in a burning car will help them escape — a risky action that promises no evolutionary benefit to the rescuers. Evolutionary biologist Jeffrey Schloss (1998) explains how Holocaust rescuers took precisely these kinds of risks:

“The rescuer’s family, extended family and friends were all in jeopardy, and they were recognized to be in jeopardy by the rescuer. Moreover, even if the family escaped death, they often experienced deprivation of food, space and social commerce; extreme emotional distress; and forfeiture of the rescuer’s attention.” (p. 251) 

A prime example is Oskar Schindler, the German businessman who risked his life and social status during World War II to prevent the deaths of hundreds of Jews at the hands of the Nazis. Why would he do this if it is ‘opposite of saving his genes’ (Cray 2006)? Schloss provides additional examples of ‘radically sacrificial’ behaviour that ‘reduces reproductive success’ and offers no evolutionary benefit, including voluntary poverty, celibacy and martyrdom (Schloss 2002, p. 221)

In evolutionary psychology, it’s often possible to conjure up an “advantage” for both a behavior and its opposite. But to explain everything and its opposite means, in the end, explaining nothing.

Rather than purpose deriving from a purposeless process like natural selection, natural selection can only occur when life itself is the result of purpose. Natural selection requires replication. But replication is a purposeful process. Purpose is defined as the reason for which something is done, created, or exists. Organisms were made to survive and to reproduce, among other things! Endowing purpose is a capability unique to agents. Every complex system, piece of architecture, or work of art arises from a purpose on the part of an agent. To highlight this point, consider the belief-desire-intention (BDI) model, which explains how rational agents act. In this model, an agent:

1. Believes a desired state can be achieved,
2. Desires that state over the current one, and
3. Intends to achieve it.

This process is familiar to us. We identify something we want, conceptualize and often document its requirements, and then balance these with constraints — whether imposed by physics, chemistry, or even a spouse! Finally, we achieve the goal through a mechanism. A purpose requires comprehension, vision, and the capacity to desire or imagine something beyond the present reality.

In biology, evidence of purpose abounds. Consider the intricate coordination of molecular processes to achieve homeostasis or how individual ecological roles contribute to the broader goals of an ecosystem. Marcos Eberlin, in his book Foresight, offers an iconic ecological example: bacteria that return molecular nitrogen to the atmosphere, completing the global nitrogen cycle.

Or, to go back to reproduction, consider the complex molecular mechanisms that are involved in cell replication. Jonathan McLatchie describes the irreducible complexity of cell division in his recent BIO-Complexity paper (McLatchie 2024). Natural selection only works because life has been endowed with the incredibly complex purposeful ability to replicate. 

As agents, we experience purpose firsthand — organizing a home, copying information to share with a friend, or assigning roles within a company. These purposeful acts not only bring order but also create new purposes for others. From this, it’s easy to extrapolate and see how the purposeful processes in biology might have originated, guided by an overarching intent that mirrors our own experiences with setting and achieving a goal.

Philip Ball also builds a case that current thinking often inserts magic as an ingredient of biology. I’ll give an example from Chapter 2, “Genes: What DNA Really Does.” This chapter critiques the reductionist view of the gene. Ball argues that biologists need to change the way they discuss life. To not change, he argues, is akin to trying to explain a great work of fiction with reference only to words, sentences, and chapters:

Words are bits of information that encode meanings. The exquisite interactions of meaning-rich words give rise to things called sentences, the most fundamental of literary entities. […] Sentences are assembled, according to the author’s blueprint, into pages and chapters, which in turn are the components of books.

While seemingly complete in some sense, the above account says nothing about how books are actually written. Ball acknowledges this and details how he thinks “magic” is being inserted into this account.

Words (+ magic) -> Sentences (+ magic) -> Chapters and Books. 

All of this he sees as a parallel to how life is being described inaccurately.

Genes (+ magic) -> Proteins (+ magic) -> Cells (+ magic) -> Tissues and Bodies.

Ball makes some excellent points, but the issue runs deeper. To truly capture how great works of fiction come into being, the term author is essential. Similarly, I suspect the only way to fully account for the origin of organisms is to invoke the concept of a designer. Without invoking an agent, any explanation will not be complete. Just as it’s impossible to fully explain the creation of a book without citing an author, the same logic applies to biology. In fact, the entire writing process described above by Ball needs to be reversed. The creation of a book goes more like this — and the same holds true for biology:

• Idea -> Outline -> Chapters -> Sentences -> Words.
• Body Plans -> Cellular Design -> Proteins -> Genes.

The writing or design process is top down, not bottom up. Without the initial idea, it would take something like magic to transform isolated words into sentences, then sentences into chapters, and finally chapters into a book telling a comprehensible story. But if you don’t believe in magic, and you do believe in agents, then to seek a clearer explanation for life, we must focus on understanding the mechanisms of agency. Practically speaking for biology, this means examining how body plans guide cellular design, how cellular design shapes protein structures, and how protein structures influence genetic frameworks. This is an application of intelligent design, where the assumption of design guides our investigations of nature, furthers our scientific knowledge, and better elucidates how natural systems work.

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