道义论

例句：

1. 1. Moral theories have been studiedextensively in philosophy.
   在哲学中，道德理论被广泛研究。
2. 2. The ethical theory ofaltruism has been a subject ofdebate for centuries.
   利他主义的道德理论已经争论了几个世纪了。
3. 3. Themorality of the actis often debated byphilosophers and scholars.
   这一行为的道义常常由哲学家和学者们进行辩论。