Hurgronje, a prominent colonial administrator best known for his study of native affairs, took Salim under his wing and arranged for him to leave the Indies in 1905 to work as an interpreter and secretary at the Dutch consulate in Jeddah, where he handled hajj affairs; in some way, it was to distance him from the radical teachings of a close relative, the well-known Shafi'i imam of Masjid al-Haram Ahmad Khatib al-Minangkabawi.

[1] Salim returned to the Indies in 1911 and pursued a career in journalism, contributing pieces for magazines and publications like Hindia Baroe, Fadjar Asia, and Moestika.

First, his newspaper Neratja had been funded in 1917 with government money (under the direction of Governor-General Johan Paul van Limburg Stirum) who wanted a Malay-language forum for perspectives sympathetic to the Dutch Ethical Policy,[3] However, by 1918 Neratja became a harsh critic of the colonial government, regularly printing reports of mistreatment of Muslims in remote regions of the Indies.

At the request of the prominent Dutch trade union Nederlands Verbond van Vakverenigingen (NVV), he served as an advisor for its delegation to the 1929 and 1930 International Labour Conventions, both held in Geneva, Switzerland.

It was alleged that throughout his early years returning from Jeddah, Salim had been in contact with or possibly working for the Politieke Inlichtingen Dienst (PID), the Dutch East Indies's principal state security and intelligence service.

Allan Akbar, a historian, conceded that Salim had been asked for a favour by Datuak Tumangguang, a prominent Minangkabau advisor to the colonial government, to covertly enter Sarekat Islam, especially to investigate the relationship between Tjokroaminoto and the Germans.

Salim found his way back to politics, being appointed to advise the Indonesian leaders (Sukarno, Mohammad Hatta, Ki Hajar Dewantara, and Mas Mansyur) who are in charge of the Pusat Tenaga Rakyat ("Center for People's Power", Putera), an intellectual body set up by Japanese government to mobilize popular support for war efforts.

Salim was appointed to the Investigating Committee for Preparatory Work for Independence (Badan Penyelidik Usaha-usaha Persiapan Kemerdekaan Indonesia, BPUPK) in March 1945.

In the committee chaired by Sukarno, Salim was one of the prominent Muslim leaders alongside Wahid Hasyim and Abdul Kahar Muzakir.

The committee would end up with the Jakarta Charter, which includes Sukarno's proposed Pancasila as official state philosophy and an explicit call for Muslim Indonesians to oblige to the sharia (ketuhanan dengan kewajiban menjalankan syariat Islam bagi pemeluk-pemeluknya).

On 11 July, Salim was appointed to sit in the Subcommittee for Constitutional Drafting (Panitia Kecil Perancang Undang-Undang Dasar), again chaired by Sukarno.

Salim did not join the first Indonesian cabinet; Sukarno, now President of the Republic, appointed him to the newly created Supreme Advisory Council (Dewan Pertimbangan Agung, DPA).

The same month, he led a small party consisting of Abdurrahman Baswedan, Rasjidi, and Nazir Sutan Pamuncak to seek diplomatic recognition from Arab states.

With the help of banker Margono Djojohadikusumo (grandfather of Prabowo Subianto), the two breached the Dutch naval blockade with a plane carrying contraband vanilla to Singapore.

"); later editions saw it updated as Keterangan Filsafat Tentang Takdir, Tawakal, dan Tauchid ("Philosophical Addresses on Tawakkul, Taqdir, and Tawhid").

His lectures were later compiled and published as Pesan-Pesan Islam: Rangkaian Kuliah Musim Semi 1953 di Cornell University, Amerika Serikat.

The marriage produced eight children: Theodora Atia (Dolly); Jusuf Taufik (Totok); Violet Hanifah (Yoyet); Maria Zenobia; Achmad Sjewket; Islam Basjari; Abdul Hadi; Siti Asia; Zuchra Adiba; and Abdurrachman Ciddiq.

Dolly, the eldest, was known for being the first person to sing the lyrics of Indonesia Raya, later adopted as the republic's national anthem, during the Second Youth Congress (Kongres Pemuda II) in 1928.

[10] Violet married Djohan Sjahroezah, a prominent socialist and underground anti-Japanese activist and a nephew of Sjahrir, Salim's revolutionary protege.

Mohammad Roem, in a piece for Prisma magazine, described the lifestyle of the man whom he succeeded as Foreign Minister as a manifestation of leiden is lijden ("leading is suffering"), an old Dutch proverb.

Salim calmly responded by asking the chair "whether Sarekat has invited a herd of goats to its meeting"; and if yes, "as a polyglot I would honour their right to listen to a speech by speaking in hircine language.

A lifelong smoker of cigar (he would sometimes lit one while teaching at Cornell[13]) a common lore was that when Salim, on behalf of the Indonesian government, met Prince Philip, Duke of Edinburgh[13] (some claimed, however, it's the other British royalties) during a dinner at the coronation of Elizabeth II in June 1953.