The "colourful gown of theory" according to Claude Chevalley

The physicist Heinrich Hertz wrote in 1892 that nature - or whatever the object of our science is - never
shows herself naked, but always clad in a colouful gown whose cut and colour is completely made up
by us. Claude Chevalley's mathematical papers are dry and forbidding; they hardly show their author
as the taylor that he was. The talk will add other, rather colourful aspects to this image of the mathematician
by looking at his whole literary production from the 1930s. The plea is for a richer, and eventually more
precise understanding of driving forces in mathematics at the time.