Simplicity, simplicity, simplicity!” Henry David Thoreau exhorted in his 1854 memoir Walden, in which he extolled the virtues of a “Spartan-like” life. Saint Thomas Aquinas preached that simplicity brings one closer to God. Isaac Newton believed it leads to truth. The process of simplification, we’re told, can illuminate beauty, strip away needless clutter and stress, and help us focus on what really matters.
It can also be a sign of aging. Youthful health and vigor depend, in many ways, on complexity. Bones get strength from elaborate scaffolds of connective tissue. Mental acuity arises from interconnected webs of neurons. Even seemingly simple bodily functions like heartbeat rely on interacting networks of metabolic controls, signaling pathways, genetic switches, and circadian rhythms. As our bodies age, these anatomic structures and physiologic processes lose complexity, making them less resilient and ultimately leading to frailty and disease.