Sentience in the history of early plant physiology: Augustin-Pyramus de Candolle's contribution

Traditionally applied to humans and some vertebrates, the concept of sentience is polysemous, and its scope has grown steadily over time. This article studies the emergence of the different faculties of sensation that developed from the field of experimental physiology in the early nineteenth century. In particular, we examine the three concepts proposed by Swiss botanist Augustin-Pyramus de Candolle in relation to plants: excitability, irritability and sentience. This tripartition is itself the result of Candolle's intellectual journey from his early experiments on the influence of light on plants in 1800 to the publication of his magnum opus on plant physiology in 1832. This work remains highly relevant, and we discuss several of its theses about plant faculty of sensation, which we bring into dialogue with contemporary biology. This allows us to recontextualise current debates on plant aptitudes in light of historical hypotheses and to rediscover possible answers.