• This target article combats some psychologists’ and phenomenologists’ blind stereotyped vision of Piag- et’s ideas on early development and the growing ignorance of his works. > Problem • The article tackles the issue of the body in Piaget’s manuscript works on infants in comparison to the contemporary theories endorsed by Gallagher. > Method • I analyze an unknown source, Jean and Valentine Piaget’s manuscript notebooks on their first child, and compare it to the contemporary theories. > Results • The method revealed itself as largely heuristic. Piaget built new relevant categories during the investigation, such as observing the child’s gaze, and the main category of observa- tion was longitudinal paths of behavior. He carefully observed transformations in the specific behaviors of each path that led to stabilize imitation in infants and he discussed self-cognition of the body, i.e., the child’s knowledge of her body, as either a curious object or her own body. > Implications • Comparing the contemporary nativist approach on early competences and Gallagher’s phenomenology to Piaget’s constructivist approach highlighted the contrast between several categories, competence versus paths and age versus processes. The investigation detected implicit epistemologies relying on priority given to age and competences over processes and path in the nativist approach, while Piaget adopted an explicit epistemology prioritizing processes and path over age and competence. A strong implication is the need to look below the surface and go beyond stereotypes towards a complex metaphor for quali- fying Piaget’s works. Against stereotypes and reification, Piaget worked mainly on paths and processes and the best metaphor to capture his conception of development is to conceive it as a temporal puzzle with new fitting pieces that shape the human subject as a multilinked network of paths. > Constructivist Content • Analyzing the founder of constructivism’s early works with a historical constructivist method led me to propose the temporal puzzle as a cognitive metaphor that synthesizes his early-development constructivist approach, both methodological and theo- retical. Moreover, since Piaget’s experimental system has never been reproduced as a whole and early development follows an implicit epistemology that is the opposite of Piaget’s, his constructivist multiple longitudinal approach remains unchallenged.