広中先生のお言葉でつ。

I am not a historian, but, roughly speaking, after World War II, up to
the 1960s and 1970s, mathematics was really by itself. It had a very strong
motive to develop by itself through internal motivations and internal interests.
For instance, Grothendieck is one person who lived by this principle. In
the 1950s and 1960s we mathematicians looked down on people who
talked about applications to the real world. If a mathematician started talking
about applications, we would say, “Oh, he stopped being a mathematician;
he has become an engineer,” even if he was doing important things.