The practical principle of morality education should be stuck to.

坚持道德教育方法的实践性原则。

youdao

instead of pursuing the questions of how exactly that theory should go, notice that if we had that theory ... we could still evaluate in principle-- whatever the practical difficulties might be-- in principle we could still evaluate rival lives.

我们不去研究,那种理论如何发挥作用，即便我们有那种理论,原则上我们仍然可以-,不管实际困难是什么-,原则上我们仍然可以评价其他生活。

耶鲁公开课 - 死亡课程节选

The e-learning programme is founded on the basic and practical principle that the use of the internet as a learning tool not only creates anonymity and thus dismantles the psychological barriers that prevent illiterate adults from resuming their studies but also enables them to balance their work, family and learning commitments by learning at home at whatever time is suitable to them.

UNESCO: Ich will lernen (I want to learn)

Young made this idea a practical guiding principle.

NEWYORKER: I, Nephi

For many scientists, however, it is the principle that counts, not the practical engineering.

CNN: Time travel: Can it really be done?