[1] As was common at the time, Van Hoogstraten later that year completed graduate studies with a Doctorate of Law after defending propositions at the same university.

[5] In Buitenzorg, Van Hoogstraten and his wife had four children: Gheret Samuel (1923-2008), Susanne Marianne (born in 1924), Jean Gustave Ulric (1927-1990) and Dirk Hans (1933-2002).

[12] The committee substantiated allegations expressed in parliament about lack of subjectivity in Aneta's press releases and the agency's misuse of its near-monopoly on facilitating access to news in colonial Indonesia.

[13] It is not clear what Van Hoogstraten's contribution to the work of the committee was, but it may have been exceptional because he was appointed Knight in the Order of the Netherlands Lion in August 1931[14] He then also became secretary of the Council of Department Directors in December 1931.

For example, during 1926–1928, he was Secretary of the private Committee for the Separation of Church and State (Commissie voor de Scheiding van Kerk en Staat).

[21] He was immediately attached to the Dutch delegation to the eventually inconclusive Hart-Nagaoka bilateral trade negotiations with Japan that took place in Bogor during September–December 1934.

The main reason for Van Hoogstraten's increased work load was the fact that Indonesia suffered badly from the global economic crisis.

Indonesia's import restrictions became increasingly detailed and also subject to regular negotiations with the Netherlands and with existing and potential trade partners such as India and Thailand (March 1936), Japan and China (May 1937) and Australia (November 1941).

It largely fell to Van Hoogstraten to negotiate the principles and details of Dutch-Indonesian economic cooperation with the Dutch government during 1939–1940.

A month later, van Mook was called to London to become Minister of Colonial Affairs in the Dutch government in exile in addition to being Lt Governor General.

It worked with the US Allied Supreme Commander of the South West Pacific Area, General Douglas MacArthur, and set out to build the Netherlands Indies Civil Administration (Nederlandsch-Indische Civiele Administratie, NICA), a public service that would be ready to move to Indonesia to assume civil administration after the war.

[27] Subsequently, Van Hoogstraten became involved in negotiating Indonesia's independence as a federal republic, which led to the completion of the Treaty of Linggarjati in November 1946.

In the process of both negotiations and planning economic recovery, he had regular contact with his counterpart in the government of the Republic of Indonesia, Adnan Kapau ('A.K.')

[32] During 1933–1949, Van Hoogstraten's life appears to have been fully absorbed by his professional duties in the public service of the Netherlands Indies and Indonesia.

He never reflected in public speeches or published interviews in any detail on what motivated him, but he appears to have dealt with a multitude of issues in a very pragmatic way.

He sustained this during the 1940s, seemingly concluding in 1946 – like van Mook – that Indonesia's independence was inevitable, and participating in the negotiations leading to the Linggarjati Agreement in 1946 and the Round Table Conference in 1949.

[33] The family disintegrated further when Van Hoogstraten most likely had to leave his two eldest children in Indonesia in March 1942, where they must have been interned by the Japanese until September 1945.