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

这是历史概括，而不是纯理论。

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

心理学从纯理论转向更仔细和系统经验观察。

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

但是我们所有谈都仅限于纯理论，没有别。

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

这些纯理论概念引领了原子理论和未实物学领域。

But the pure theory of what determines the actual employment of the available resources has seldom been examined in great detail.

但是，很少详细研究决定可用资源实际使用纯理论。

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

对于纯理论书籍，同意或不同意标准与所讲内容真实性有关。

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、主要命和论证书籍，当然看起来与纯理论书籍中完全相同。