If Peirce had a general rationale for his triadism, Peirce scholars have not yet made it abundantly clear what this rationale might be.    From Wordnik.com.  [Nobody Knows Nothing] Reference

He seemed to base his triadism on what he called “phaneroscopy,” by which word he meant the mere observation of phenomenal appearances.    From Wordnik.com.  [Nobody Knows Nothing] Reference

The full philosophical import of his Reduction Thesis, and the philosophical importance of his triadism insofar as this triadism rests on his Reduction Thesis, cannot be ascertained without a prior understanding of his non-typical theory of identity and his special view of the fundamental nature of the relative product operation.    From Wordnik.com.  [Nobody Knows Nothing] Reference

“triadism.”.    From Wordnik.com.  [Nobody Knows Nothing] Reference