Based on Vygotsky's theory of the interplay of the tool and sign functions of language, this study presents a textual analysis of a corpus of student-authored texts to illuminate aspects of development evidenced through the dialectical tension of tool and sign. Data were drawn from a series of reflective memos I authored during a seminar for new doctoral students designed to encourage the development of their identities as educational researchers. In an effort to understand how the tool and sign functions played out in this developmental context, I employed three methods of analysis: (a) I parsed them into evidential units of induction or deduction, (b) I positioned each unit on semantic differential scales to indicate the assumptions and authorial roles manifested, and (c) I examined how these positions were discursively realized through problematizing, intertextual reach, procedural membership, and reciprocal membership. The analysis demonstrates how examining the dialectical relationship of tool and sign illuminates the developmental trajectory of a student writer.