The provided text outlines Chapter 2 of the Texas Penal Code, which addresses the Burden of Proof in criminal proceedings. This chapter establishes the fundamental principle that all individuals are presumed innocent and can only be convicted if every element of an offense is proven beyond a reasonable doubt. Furthermore, the statutes distinguish the procedural requirements for exceptions to an offense, which the prosecuting attorney must negate and prove non-existence, from a regular defense to prosecution, where the prosecutor is not required to negate its existence and the issue is only submitted to the jury if supporting evidence is admitted. The code also defines an affirmative defense, which requires the defendant to prove it by a preponderance of evidence, and details the consequences of presumptions for both the state and the defendant regarding how facts must be presented and charged to the jury.