Open peer commentary on the article “A Temporal Puzzle: Metamorphosis of the Body in Piaget’s Early Writings” by Marc J. Ratcliff. Abstract: In this commentary, I would like to know more details of the role of temporality and the social dimension of the body in Piaget’s early works, notably on the content of the notebooks written by Piaget and his wife, Valentine. Through diachronic-synchronic concepts drawn from linguistics, I propose a discussion of the methodological problems of Piaget’s observation method, as presented by Ratcliff. In principle, taking a look at the methodological steps through these concepts could greatly contribute to the reflection on Piaget’s units of analysis and thus to his interpretation of the emergence and coordination of the multimodality of skills.