Descartes, Plants, and the Meaning of the French Garden

Adamson explains that Aristotle linked plants' lack of motion to their lack of sensation, since they absorb nutrition from soil rather than pursuing food, leaving nutrition and reproduction as their two main functions. This view was extended by Theophrastus, Dioscorides, Avicenna, and Albert the Great, and shaped early modern botany even as new tools like the microscope and colonial specimens expanded empirical knowledge.

Descartes planned to include plants in his Principles of Philosophy and conducted botanical experiments with a collaborator, developing mechanistic explanations such as hoeing mixing soil particles to improve flavor. His broader theory held that plants have countless tiny ducts conducting juices that dry into leaves, flowers, and fruits, explaining differences between land and water plants without invoking any vegetative soul.

Because the mimosa's leaf-closing motion seemed animal-like, Scholastics like Guillaume Duval debated whether it had a plant or animal soul, with Duval attributing the motion to a brute force like magnetism rather than genuine animal power. Descartes and his disciple Regius instead explained the motion mechanistically, as agitated particles inside the leaves sifting downward and pulling them closed, eliminating the need to classify the plant as animal or vegetable.

Adamson notes the irony that as mechanism eroded strict plant-animal boundaries, naturalists like Caspar Bauhin were classifying thousands of plant specimens by physical features, though still organizing categories around Aristotelian nutritive and reproductive powers. Institutions like the Jardin du Roi, founded in 1626, became long-running centers of botanical research and later colonial collection under figures like Buffon and Adanson.

Adamson argues that Versailles-style gardens, with their flat plains, geometric beds, and precisely engineered water effects, make visible the underlying geometrical structure that Cartesian physics attributes to nature. He contrasts this with Kant's later preference for the sublime disorder of English gardens, which reject the French garden's rigid mathematical regularity.

Adamson describes how 17th-century French gardening treatises by garden designers combined geometrical proportion with practical advice, reflecting the idea that nature itself combines order and diversity. This produced gardens with varied plots, entertainments, and optical tricks like terraces sized to appear uniform from a distance, following the logic of perspective.

Adamson argues that Versailles was built partly to outdo the finance minister Fouquet's garden at Vaux-le-Vicomte and to demonstrate the king's power over aristocracy, land, and nature. Military engineering techniques used for battlements and moats reshaped the gardens' land and water, while solar imagery casting Louis XIV as Apollo and perspectival design pointing toward the setting sun reinforced his political and cosmic authority.

Guillaume Duval argued the mimosa's leaf-closing is due to a brute natural force like magnetism or weight rather than a genuine animal power, staying within a framework that still distinguishes plant and animal souls. Descartes and Regius rejected any soul-based explanation at all, treating the motion as purely mechanical particle agitation, dissolving the need to classify the plant by soul type.

Kant criticized French formal gardens for their stiffness and mathematical regularity and praised English gardens for capturing nature's sublime disorder. Adamson notes that a thinker more wedded to Cartesian philosophy would instead celebrate the French garden for revealing nature's underlying geometrical principles.