With minor ailments the best thing is often to let nature take its course.

对于小病，往往最好是听其自然。

《牛津词典》

Just let nature take its course.

就顺其自然吧。

《牛津词典》

Sometimes, let nature take its course, and you will know if it is worth having.

有时候，顺其自然，你才会知道那些事是否值得得拥有。

youdao

So in those circumstances, I'm an advocate of active euthanasia. I think it is just as if you have a dog who was dying from some disease, you wouldn't say, well we just let nature take its call.

所以这种情况下，我通常会,支持安乐死，我认为,这就像是你的狗得了病,马上就要死了，你不会说，嗯，我们顺其自然吧。

普林斯顿公开课 - 人性课程节选

Some critics feel that this operation is no better than letting nature take its course.

ECONOMIST: Trial and error

The idea behind it was that we can make roads fit for people by letting human nature take its competent and co-operative course.

BBC: Viewpoint: Is it time to get rid of traffic lights?

So to all those getting worked up about them, just sit back and let nature take its course, safe in the knowledge that the only thing more certain than Hear'Say breaking up, is the fact that there will be five more new manufactured bands waiting to take their place in the sun for a few months.

BBC: Hear'Say: Your views