On Revisiting Gödel's Incompleteness and Turing's Undecidability of the Halting Problem: A Foundational CritiqueNOTE: A major revision (Version 6) is currently in preparation. The new version will include a strengthened proof of the Doubled Diagonal Lemma Executive Summary: This work presents a systematic re-examination of the logical foundations of classical limitative results. Through detailed technical analysis, it demonstrates that Gödel's incompleteness theorems and Turing's halting problem undecidability arise not from inherent limitations of formal systems, but from specific, non-neutral commitments in their meta-theoretical framework (ZF_ω). The paper introduces the "Doubled Diagonal Lemma" and shows how diagonalization, when applied consistently, leads to contradictions that challenge the coherence of classical metamathematics. Abstract This paper establishes a rigorous formal foundation for the interplay betweenrecursive function theory, Turing computability, and Peano Arithmetic. We beginby constructing the class of recursive functions via closure operations, proceedingto formalize their arithmetization through Gödel numbering and the EnumerationTheorem. Building upon the Church–Turing Thesis, we demonstrate the existenceof a universal partial recursive function and its corresponding Universal Turing Machine. The paper then transitions into the formal system of Peano Arithmetic,where we develop a detailed Gödel numbering of the language and metamathematical predicates, enabling the internal representation of syntax and proof structures.Key results include the formalization of Kleene’s Normal Form Theorem within PAand a comprehensive analysis of the representability of recursive functions and predicates. In later sections, we undertake a granular re-examination of self-referencemechanisms, exploring the structural behavior of diagonalization under varying logical constraints. This work serves as the first in a series(at least two papers) ofinvestigations into the logical, and philosophical foundations of mathematics, computability and formal systems. Key Contributions 1. **The Doubled Diagonal Lemma** (Theorems 9.1 & 9.2): Demonstrates that any classical diagonal fixed point satisfies a second-order fixed point property, revealing hierarchical self-reference. 2. **Foundational Analysis**: Shows that provability predicates in Peano Arithmetic lead to contradictions when subjected to doubled diagonalization, while halting predicates admit consistent simulation-based resolutions. 3. **Type-Theoretic Critique**: Exposes fundamental type confusions in classical diagonal arguments between numbers, numerals, and their encodings. 4. **Historical-Philosophical Synthesis**: Traces the foundational crisis from Plato/Aristotle through modern set theory, arguing that the mismatch between Aristotelian logical language and Platonist ontological commitments generates apparent paradoxes. Paper Structure - Sections 1-8: Construct classical apparatus (recursive functions, arithmetization, PA formalization) - Sections 9.1-9.3: Technical analysis of diagonalization (Doubled Diagonal Lemma) - Sections 9.4-9.5: Critique of arithmetization under Replacement axiom - Section 10: Reflexive critique of ZF_ω as meta-theory - Section 11: Philosophical synthesis and implicationshttps://github.com/marwanezerradi2/undeciability-incompleteness-diagonalization Note This is a comprehensive, self-contained work (69 pages) that builds the entire classical framework before critiquing it. It is presented as a preprint for community feedback and discussion, I do not claim the absolute correctness I followed the Ideas and Logic where they led me.**Note on Versioning:**This work may evolve through subsequent versions as technical feedback is received,or via the author's own refinements upon further reflection or technical remarks.Significant corrections or substantive edits will be released as new versions,clearly indicated in version history. The latest version should always be consulted for discussion. For contact : marwanezerradi2@gmail.com Version History : (V.2) : Fixed some minor notations faults