na-adjective
discursive; argument-based
Describes reasoning that proceeds by logical argument rather than intuition or direct experience. A somewhat academic term.
彼の説明は論弁的で、直感的な理解が難しかった。
His explanation was discursive, making intuitive understanding difficult.
この哲学書は
This philosophy book is written in a discursive style.
論理的 means 'logical' and is more common; 論弁的 specifically emphasizes the process of argumentation.
Compound of 論弁 (argument, discussion) + 的 (-like, -tic). The exact historical derivation is uncertain; the spelling is conventionally associated with discursive reasoning.