Topology was originally studied as a branch of purely abstract mathematics.
拓扑学最初是作为纯抽象数学的一个分支来研究的。
英语百科
Pure mathematics
Broadly speaking, pure mathematics is mathematics that studies entirely abstract concepts. This was a recognizable category of mathematical activity from the nineteenth century onwards, at variance with the trend towards meeting the needs of navigation, astronomy, physics, economics, engineering, and so on.