Since Edward Said it is quite common to write in a critical way about colonial views of Asia and African, especially Muslim societies. Ahmad Baso joins here Husnul Aqib Suminto and Michael Laffan, who wrote about colonial management of Islam. He often also discusses my book on Dutch Colonialism and Indonesian Islam, 1596-1942. But he does not write history for the sake of history, he wants to formulate a fresh view on 'Islamic Law', as it was under Dutch colonial administration and as he wants to see it himself now.
I give here a personal interpretation from two sections First is in chapter five about "polisi" Kolonial, which is, I suppose, not about colonial police, but colonial policy. Lodewijk "LWC" van den Berg is quoted as someone who invented or reestablished the terminology of receptio in complexu: Indonesian people accepted (receptio) Islam and so they also embraced the full package or shari'a rules (see p. 296). This was against the ideas of his successor Snouck Hurgronje who separated adat from the practice of shari'a. Snouck also did not like to talk about Islamic Law, but used the word plichtenleer, 'the collection of cultural prescripts'. In this field Ahmad Baso joins the interpretation of Snouck: Islam is not a legal system, comparable to modern law. It is more spiritual, and flexible rather than the modern system of law where not easily change can be introduced.
Whether LWC van den Berg really promoted a full receptio in complexu can be debated. He knew that only marriage and divorce, besides inhertiance were ruled as such in the Indonesia of the 19th century (and perhaps: only Java and Madura, because in Minangkabau and even in Aceh there were interferences of matrilineal practices in marriage law).
Anyway: Ahmad Baso behaves like a pupil of Snouck Hurgronje and puts much of shari'a or Islamic Law under the more flexible rule of adat.
Pages 325-332 are difficult to read for me, but are probably basic for Baso's argument that there is not such a thing as a fixed 'Islamic Law' but rather a much more flexible cultural institution. Most important is the debate about marriage, before and after 1974 when the new law was promulgated. The whole debate started with a controverse: whether there should be secular or Muslim Law in this field. But what came out of it is a mistifikasi dan sakralisasi, menjadi 'Hukum Tuhan'. It turned into a mystification and a sacralisation: a Divine Law (page 326).
This debate puts the question again: in what fields does religions have authority, and how far can they give directives? In our European society we see hot debates now about marriage also for homosexuals: things remain changing in matters that are also claimed by specialists in Islamic Directives (Shari´a'. ).