Jan Jakob Maria de Groot (1854-1921) was a Dutch Sinologist and historian of religion. He taught at Leiden University and later in Berlin, and is chiefly remembered for his monumental work, The Religious System of China.
De Groot maintained that one spiritual essence ("universism") could be detected beneath a great variety of religious and philosophical expressions in China. He made is his lifework to discover that essence.
At the end of the 19th century, he and Schlegel were the chief Sinologists in Leiden; however, in 1902 De Groot moved to Berlin, where he would stay until the end of his life.
The Religious System of China is of course dated, but still contains interesting elements and can serve as an introduction to the traditional Chinese "universe."
Here is his magnum opus in six volumes (and in fact, incomplete):
Volume I, Book1A "Funeral Rites"
Volume II, Book 1C: "The Grave, part 1"
Volume II, Book 1C "The Grave, part 2"
Volume IV, Book 2A: "The Soul in Philosophy"
Volume V, Book 2B "Demonology and Sorcery"
Volume VI, Book 2D and 2E: "The war against specters"