Why this 17th-century philosopher believed you are merely a spectator of your own body

Ideas & Philosophy · Published 3 October 2026 Swipe more like this →

In short: Arnold Geulincx was a Flemish thinker who argued that because we do not understand how our nervous system triggers muscle movement, we cannot possibly be the cause of our own physical actions. Instead, he proposed that God acts as the true engine behind every human movement and decision.

Born in Antwerp in 1624, Arnold Geulincx was a prominent figure in the Cartesian tradition, though he eventually steered his philosophy toward a stark, ascetic worldview. After losing his professorship at the University of Leuven in 1658—likely due to his religious sympathies—he moved to Leiden and converted to Calvinism. Living in poverty for several years, he eventually secured a position as a professor of philosophy and ethics, where he developed his unique brand of occasionalism.

Geulincx’s core argument rests on a principle of causality: if you do not know how a process occurs, you cannot be the one performing it. Since we are ignorant of the biological mechanisms that translate a mental impulse into a physical contraction, he concluded that we are essentially spectators of our own bodies. In his view, God provides the 'occasion' for our actions, serving as the hidden force that makes our will effective. This perspective led him to advocate for an 'ethics of humility,' where the primary goal is to recognize our own impotence and submit our will to the authority of reason.

This philosophy of detachment deeply influenced later writers, most notably Samuel Beckett, who frequently cited Geulincx’s maxim: where you have no power, you should have no desire. Unlike Leibniz, who later used similar concepts of pre-established harmony to argue for an optimistic view of the world, Geulincx remained focused on the limitations of the human condition. His work, often published under the pseudonym Philaretus, remains a challenging meditation on the divide between our internal intentions and the external world we inhabit.

Though he was criticized by contemporaries who feared his ideas bordered on Spinozism or anti-Christian thought, Geulincx’s influence persisted through the centuries. His emphasis on self-renunciation and the mechanical nature of the body offers a striking, if gloomy, counterpoint to the Cartesian belief that human reason could achieve total mastery over the material world.

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