人皆謂孟子好辯，但孟子自己卻說：「予豈好辯哉？予不得已也。」孟子之辯是逼不得已的。孟子身處戰國之世，邪說暴行充斥，已到了「仁義充塞」、「率獸食人」之境地，孟子乃是為仁義之道而辯，為「正人心，息邪說」而辯。 孟子與楊墨之徒辯，與農家、縱橫家辯，與告子、高子辯，因為諸家之言論、主張都是「舉一而廢百」的，是一偏之見，未能全幅肯定人文精神的意義，故孟子以儒家仁義之道，向諸家重新肯定人倫、人格之意義。 孟子對人性有信心，相信人有反省能力，能夠判辨是非曲直。因此人也許會一時被偏見所蔽，但必有能力理解和實踐仁義。因此，孟子運用反詰、設問、對比、設譬等方法，引導人作自我反省，使之通過自己的思考以掌握仁義之正理。孟子之辯，是站在仁義之道而辯，是為人文價值而辯。

People said that Mencius was fond of arguing but Mencius denied. However Mencius have to arguing with the fashionable ideas in order to advocating Confucian thought. Mencius argued for benevolence and righteousness. Mencius argued with Yang and Mo (楊墨之徒), with Husbandry School (Nongjia 農家), with Strategist, with disciple Kao (高子) and scholar Kao (告子), because their sayings were "to take up one point and to disregard a hundred others", which was a one-sided judgement, unable to recognize the significance of humanism on the whole. Therefore, Mencius used the idea of benevolence and rightousness of Confucian, to ensure the significance of human relations and the value of morality. Mencius had faith in human nature. He believed that everyone has the ability to introspect, to identify what is right, what is wrong and to make correct judgement. Hence, one may be blindfolded by prejudiced idea for a while, but he will have the ability to comprehend and to fulfill benevolence and righteousness. Therefore, by setting up questions, rhetorical questions, using metaphors and making contrast, Mencius advocated people to contemplate the meaning of benevolence and rightousness.