Psychology shifted away from pure theory and towards more careful and systematic empirical observation.

心理学从纯理研究转向了更加细致和系统化实证观察。

But all our talk was limited to pure theory and nothing else.

但我们仅限于纯理，没有其他内容。

These purely theoretical concepts led the way to  atomic theory and the unfulfilled biology field.

这些纯理概念引领了原子理和未实现生物学领域。

But many participants in The Republic of Letters were focused on less theoretical matters.

然，“书共和国”中许多参与者更关注是实际非纯理问。

This is a question for historical generalisation rather than for pure theory.

这是历史概括问，是纯理问。

In the case of purely theoretical books, the criteria for agreement or disagreement relate to the truth of what is being said.

对于纯理书籍，同意或同意标准与所讲内容真实性有关。

I don't think that was wrong, you know, back months ago, to highlight in pure theory, a one-time tariff is a one-time increase in cost.

我认为几个月前从纯理角度强调一次性关税是一次性成本增加并没有错。

Why did they satisfy themselves with the meager theory of positive external effects as a corollary of the equally pitiable theory of pure and perfect competition?

为何他们满足于将正外部效应这一贫乏理作为同样可悲纯理和完全竞争理附属品呢？

In the other kind of practical books, the kind dealing mainly with the principles underlying rules, the major propositions and arguments will, of course, look exactly like those in a purely theoretical book.

在另一类实用书籍中，主要涉及规则背后原理、主要命和证书籍，当然看起来与纯理书籍中完全相同。