The English word “agency” derives from the Latin agere, meaning “to act” or “to drive”, and traces back to the Proto-Indo-European root *ag-, signifying “to lead or move.” In the 1600s, its sense shifted. It drew on alchemical imagery where the agent stood as the active substance that could turn the ordinary into gold. The term also began to describe the mediator in negotiations of influence. Consequently, agency as a concept acquired a more dynamic quality, moving from mere effect to active incitement. In this way, the word also came to signify power.
So, here is the core point. When we consider the deliberate actions of living beings, we are also confronting political and ethical questions about the ability to influence or direct our own conduct and the conduct of others. This matters a great deal for humans, who are highly sensitive to judgments of authority and strength, and much depends on whether we believe another being can take an active part in altering outcomes.
Yet the shifts in meaning also mirror a recurring tendency to search for some special force or external driver beyond the body itself.
Many living beings possess ingrained mechanisms for detecting agency that can mislead them, yet their aim is to identify entities that have their own goals.
Aristotle was not immune to such questions. In his Metaphysics, he wondered if there exists an ultimate cause beyond the psyche, particularly in what moves the heavens: “There is something which is always moved with an unceasing motion, and this is moved by the Unmoved Mover.” Many have taken this enigmatic figure to be Aristotle’s God—an ultimate agent, the original source of action. His occasional use of the term theos lends support to that interpretation.
Yet what intrigues is that Aristotle’s God is not a conventional divine being who commands and shepherds. Instead, his deity might better be understood as a personification of the source of energeia—the furthest horizon of fulfillment toward which all potential forms in the universe strive. This is not a creation event per se, but an enduring principle of motion and transformation.
Perhaps a contemporary analogy lies in the search for a unifying field or constant that underpins all forces in physics. Paradoxically, Aristotle’s obscure term reappeared in science as “energy”, though its modern, quantitative meaning differs markedly from the metaphysical sense he had in mind.
Nevertheless, for centuries the question of agency in living organisms has persisted. If there is a goal at work, who generates it in the first place? And if the goal carries meaning, where does that meaning reside? What makes a frog leap from one bank to the other, or what prompts you to pick up this book and read it? Who or what or where is the agent?
If we treat these questions seriously, we are compelled to enter some especially tricky terrain. A helpful starting point is to examine how we detect an agent in physical terms.
Researchers who specialize in “agent detection” have pinpointed particular brain regions, such as the ventral temporal cortex, and neural networks like the action observation network that activate when an animal is identifying the source of an action. But animals don’t seem to care about every form of motion, such as a boulder tumbling or wind rushing through a corridor. What appears to happen is that animals recognize an action and then seek its cause, yet the causes that matter most are those tied to living organisms. In short, life seeking life seems to be a priority for many species.
That the methods sometimes miss is not proof that the category of life is too narrow; rather, what emerges from evolution as organisms’ bodies change over time is often good enough rather than perfect. Yet we can observe that if an animal can determine that a lifelike object is not another animal, its interest wanes.
The distinction matters because it hinges on purpose. When a living agent is being judged, many animals, especially mammals, observe behavior to infer another being’s intentions and anticipate future actions: Are they a threat? Are they calm or aggressive? What will they do next?
Part of this involves mapping others’ actions onto our own possibilities—given what they are doing, what might we do? This isn’t merely because living agents are less predictable than a waterfall, but because their goal-driven nature broadens the scope of possible choices beyond what is produced by external forces alone.
Consider an antelope: you cannot be sure it will not suddenly alter course, head straight toward you, or slip onto another path. A living creature continually reevaluates its situation and modifies its behavior. Anticipating what matters to another being—their motives and limits—helps forecast what they might do. This awareness is vital for animals, especially those that hunt or are hunted.
When I was a child, my cat Phoebe treated the vacuum cleaner as if it were a living thing. It moved, made sounds, and seemed to devour items from the floor. In short, it appeared to possess some of the traits of life. Phoebe shadowed it at a careful distance, watching warily. When the machine paused, she edged closer to sniff, initially with hesitation. But once she confirmed it wasn’t alive, she wandered off, uninterested. She never repeated that category error.
It mattered little to Phoebe that the vacuum exhibited life-like features. She was seeking the entity driving the events—not merely something causing an effect, but a being with reasons to act. When Phoebe realized that the vacuum cleaner was connected to me and that I was the one operating the device, her interest waned. The act of cleaning the room was my objective, not the vacuum’s.
And so, many living beings sustain ingrained ways of detecting agency that can mislead them, but their aim remains to locate entities with their own goals. This does not require a brain so much as a body with purpose.
When clarity is lacking or the environment is unpredictable, we tend to attribute agency to a wider range of phenomena.
Yet for humans the situation is distinct. We concentrate intently on what transpires inside our own heads, where conscious intentions fuse. For a highly social species like ours, it pays to anticipate what another might intend. Recognizing others’ values and goals has shaped the way we interpret the world. We do not merely scan for life; we scrutinize behavior and form for signs of mental agency. Paradoxically, this has left us prone to over-detecting both life and agency, as Jiangang Liu and colleagues demonstrated in a 2014 study. We perceive faces everywhere—for instance, in an oncoming car, a fire hydrant, or the clouds. This is not a straightforward case of pattern recognition. The same line of inquiry shows that such judgments involve assumptions about intention and expression, not just facial similarity, and this tendency appears to intensify under conditions of uncertainty.
When ambiguity or unpredictability dominates the environment, we incline to see agency in a broader array of phenomena, including lightning storms and even a rubber tire rolling down a slope.
In their 2010 investigation into animism, the neuropsychologist Patricia Helvenston and archaeologist Derek Hodgson argued that several ancestral adaptations for distinguishing between living and non-living forms gave rise to a pre-adapted cognition that constantly scans the environment, largely below conscious awareness, for signs of life.
Other research has shown that extending agency to non-living entities or materials increases under conditions of high uncertainty. Anthropologist Nurit Bird-David notes that perceiving and then building models of social relations among humans, non-humans, and the broader environment can offer practical means of navigating a world that is inherently fluid and potentially threatening.
This view is supported by experimental work in Western industrial societies by psychologist Vernon Padgett and economist Dale Jorgenson. Their surveys reveal that periods of greater insecurity—such as times of economic strain—correlate with a rise in belief in non-physical, spiritual, or magical forces. The contemporary Western expansion of what counts as life or agency likely has multiple causes, including a spiritual void, a magnified sense of individual primacy, and inflated expectations about artificial intelligence. It is also plausible that the current trend relates to the vulnerabilities of a world shadowed by an impending environmental crisis.
In any case, what these studies encourage is an awareness that humans (and other social mammals) may be unusually predisposed to perceiving signs of mental agency.
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From Alive: The Hidden Intelligence of the Living World by Melanie Challenger. Copyright © 2026. Available from Penguin Books, an imprint of Penguin Publishing Group, a division of Penguin Random House, LLC.
