This is true in theory, but not in practice.

这在理论上是真的，但却不是事实。

youdao

And the second part of the book is devoted to India's speciality: ideas that have prevailed in theory, but not in practice, leaving reformers with nothing more to say, but plenty still to do.

本书第二部份著重探讨印度的专长：理论充满创意，却都没有实行，让改革家已经无话好说，却还有一大堆需要去做。

youdao

youdao

Dr. David Hunter says he has not seen an increase in his practice as a pediatric ophthalmologist at Children's Hospital Boston.

VOA: special.2011.08.01

We can talk about "religion-ex" since everybody is spiritually equal, but women and men actually in practice are not equal.

我们可以说说“宗教性别“,在精神层面上，人人都是平等的，而实际上女人和男人是不平等的。

普林斯顿公开课 - 人性课程节选

The decay of Christian belief and practice is not a loss but rather an opportunity for poetry, in Crane.

基督教信仰和践行的衰败,在克莱恩看来，并不是损失，反而是诗歌新生的机会。

耶鲁公开课 - 现代诗歌课程节选

Note that right at the outset the public interest comes first ( at least on paper, if not in practice).

FORBES: Have They Pushed the Self Destruct Button at the International Financial Reporting Standard Foundation?

In a society, a lot of times we have to step back and ask ourselves if what we're doing in principle, not in practice, is right.

WHITEHOUSE: Online Town Hall

It is there on paper but not in practice.

FORBES: Timing Is Everything