Robert Burch describes Peircean Algebraic Logic as a language to express Peirce's “unitary logical vision” , which Peirce tried to formulate using different logical systems. A “correct” formulation of Peirce's vision then should allow a mathematical proof of Peirce's Reduction Thesis, that all relations can be generated from the ensemble of unary, binary, and ternary relations, but that at least some ternary relations cannot be reduced to relations of lower arity.Based on Burch's algebraization, the authors further simplify the mathematical structure (...) of PAL and remove a restriction imposed by Burch, making the resulting system in its expressiveness more similar to Peirce's system of existential graphs. The drawback, however, is that the proof of the Reduction Thesis from Burch no longer holds. A new proof was introduced in Hereth Correia, and Pöschel and was published in full detail in Hereth .In this paper, we provide proof of Peirce's Reduction Thesis using a graph notation similar to Peirce's existential graphs. (shrink)