Complex sentence: Its main objective, for Peirce, is to classify arguments and determine the validity and force of each mode which he divides into three main modes: abductive inference (guessing, inference to a hypothetical explanation); deduction; and induction.
Split into simpler sentences: Its main objective, for Peirce, is to classify arguments and determine the validity and force of each kind. He sees three main modes: abductive inference (guessing, inference to a hypothetical explanation); deduction; and induction.