 He was a close advisor to J. H. Oldham and was deeply involved in the conference in London in 1923 that declared the paramountcy of African interests in Kenya.He sat on various councils and served (from 1924–1926) as representative of African interests on the Legislative Council of Kenya and (1928–1929) on the Kenyan Executive Council.Arthur was particularly concerned with problems of education, land ownership and labour reforms, and was involved in debates over the practice of female genital mutilation amongst the indigenous population.