This chapter examines the history of Marie-Yvonne Vellard, an Aché girl from Paraguay who was captured in the 1930s at the age of two and raised by a French scientist named Jehan Albert Vellard. By examining the various retellings of Marie-Yvonne’s story and the many stories of captured children that populate ethnographic studies of the Aché, this essay tracks how colonial violence against Indigenous peoples was repackaged within a ostensibly antiracist framework. While the redemptive accounts of her story did important work by challenging biological determinism, they also concealed how the practices of mid-century human scientists sometimes encouraged the forced removal of children from their families and the dispossession of Indigenous territory. In fact, as this chapter demonstrates, until the 1960s ethnographic studies of the Aché were based primarily on captured children and attest to an established practice and economy of buying and trading Aché children as servants. Although researchers who studied captured Aché children positioned themselves as civilized men of science, they did not condemn the trafficking of Aché children that they benefitted from and instead presented it as a fait accompli that they could only observe as modest witnesses.

The Preface outlines the origins, motivations, history, and stakes of the project that led to the publication of this book, and it discusses the project’s relationship to scholarship in Indigenous Studies and engagement of key works in that field. It explores what an approach informed by Indigenous Studies can bring to the history of the human sciences, and how it might build upon existing scholarship on this topic.

In this conclusion, Stephen T. Casper reviews themes and findings from the entirety of the collection. He situates the book as a whole as a provocation to reconsider the traditional historiographic approach in the history of the human sciences.

The application of the word ‘development’ to a fully formulated principle of temporal Order becomes ubiquitous in Rousseau’s Emile. The biologist Buffon, the psychologist Condillac and particularly Bonnet all influenced this seminal treatise. But where they had written of development only occasionally and in an abstract sense, with Rousseau it becomes normative and the main descriptor of the structured lifespan of the individual. Rousseau retains the older sense of development as the ‘unfolding’ of an already existing, preformed structure; nevertheless, he also reveals in outline the modern human sciences’ presupposition that the child is an incomplete being. Thanks to Bayle and Diderot, Rousseau derived his concept of a political General Will, irrespective of the individual will, from that of God’s general will to save humankind that does not take individual behaviours into account; this has its psychological equivalent in Rousseau’s creation of ‘the abstract man’, against whose developmental norms the individual must be measured.