Machines are built from parts. Humans are made of food. That distinction runs to the heart of one of the deepest questions in biology: can the experience of being alive, and specifically the visceral instinct to eat, be fully explained by mechanisms?

We argue that it cannot. At least not yet, and perhaps not ever in isolation. Beginning with the molecular revolution and the reductionist tradition that followed Schrödinger’s What is Life?, it traces how biology came to describe living organisms in terms of signaling pathways, receptors, and genetic programs. These tools have been powerful. They have revealed the neuropod cell, the gut-brain synapse, and the neural circuits that drive food choice in milliseconds. But they have not explained the birthday cake baked in the company of friends, or the comfort of a warm cookie on a cold day.

To make that case, we reach outward to Walter Cannon’s concept of “voodoo death,” to the ritual practice of zombification in Haiti, to the ethnobotany of the Amazon, and to Indigenous knowledge systems that have long understood humans as inseparable from the natural world and from what they eat. These are not digressions, but evidence that the experience of eating is biological, psychological, cultural, and spiritual at once.

In the era of artificial intelligence, the stakes of this question have sharpened. We can build machines that replicate our functions. We cannot yet program them to feel. That gap between mechanism and experience is where the most interesting questions about life still live.

https://genesdev.cshlp.org/content/38/17-20/798.full#xref-fn-1-1