Buck never allowed himself to be bullied into doing anything that went against his principles.

巴克从来不会因为受到威胁而做违背自己原则的事情。

...moral principles.

道德准则

It's not just a matter of principle.

这不仅仅是原则的问题。

...a man of principle.

讲究原则的男人

...a violation of the basic principles of Marxism. [+ of]

违背马克思主义的基本原则

The doctrine was based on three fundamental principles.

这个学说建立在三条基本原理之上。

These people lack all understanding of scientific principles. [+ of]

这些人对科学原理一窍不通。

...the principles of quantum theory.

量子论原理

I agree with it in principle but I doubt if it will happen in practice.

我大体上同意这一点，但是怀疑它是否能够付诸实践。

Even assuming this to be in principle possible, it will not be achieved soon.

即使假定这在理论上行得通，它也不可能于短期内实现。

He would vote against it on principle.

他会根据原则投反对票。

His father, on principle, did not like to hear requests for money.

从原则上来说，他父亲不喜欢别人借钱。