Jan C. Smuts, statesman, soldier, philosopher and amateur botanist, was the son of Jacobus Abraham Smuts and his wife Catharina P.G. de Vries. He was taught by his mother until the age of twelve, then attended school in Riebeek West and in Stellenbosch, passing the matriculation examination of the University of the University of the Cape of Good Hope in 1888. Continuing his studies at Victoria College, Stellenbosch, he was awarded the BA degree in Literature and Science by the University of the Cape of Good Hope in 1891 and earned the Ebden Scholarship that enabled him to study further at the University of Cambridge. During the five years he spent at Stellenbosch he met H.W. Rudolf Marloth* and accompanied him on plant collecting excursions, which led to his life-long interest in the indigenous flora of South Africa.
Smuts qualified in law (LLB, 1894) at Christ's College, University of Cambridge, with an outstanding academic record and practiced as an advocate in Cape Town (1895-1897) and in Johannesburg (1897-1898). During these years he became active in politics and in June 1898 was appointed state attorney of the South African Republic (Transvaal), a position he held until the republic came under British control during the Anglo-Boer War (1899-1902). After actively participating in the war he practiced law again and in 1907 became colonial secretary and minister of education in the government of the Transvaal Colony. He played a key role in drafting the constitution of the Union of South Africa and served in various ministerial positions in the Union government. During World War I (1914-1918) he led part of the campaign in German South West Africa (now Namibia) and then took over the command in east Africa with an appointment as lieutenant-general in the British army. Subsequently, as a member of the War Policy Committee in London, he proposed a plan which became the basis for the League of Nations. After the war he served as prime minister of South Africa for five years (1919-1924).
After his party lost the general election in 1924 Smuts had some leisure time in which to resume his botanical studies. This resulted in his becoming an authority on South African grasses. The philosophical ideas that he had been developing since his stay in Cambridge were written up in a book entitled Holism and evolution (1926) in which he described holistic evolution as a cosmic process of individuation extending from the inorganic (matter), through the organic (life), to the mental (mind). Holism (or wholeness) was seen as a fundamental factor in the universe, leading to the creation and self-perfection of wholes through an evolutionary process.
Smuts became a member of the South African Association for the Advancement of Science in 1905 and served as its president in 1925. His presidential address was entitled 'Science from the South African point of view' (South African Journal of Science, 1925, Vol. 22, pp. 1-19) and included a discussion of the mystery of the origin of the Cape flora. By 1917 he was a member of the Royal Society of South Africa. In January 1923 he became a member of the South African Biological Society and by 1924 was a member of the Astronomical Society of South Africa. Later he wrote an obituary of the astronomer A.W. Roberts* for the Journal of the Astronomical Society of South Africa (1938). At the joint meeting in South Africa of the British and South African Associations for the Advancement of Science in 1929 he served as joint vice-president of both Section E (Geography) and Section K (Botany) and opened the discussion on 'The nature of life'. In 1930 he was elected a Fellow of the Royal Society. The next year he served as president of the British Association in its centenary year (1931), his presidential address dealing with 'The scientific world picture of today'. He and the archaeologist Clarence van Riet Lowe returned to South Africa on the same ship and held daily meetings to discuss prehistory and the problems of climate and environment in which Smuts was particularly interested. In 1932 he delivered an evening discourse on 'Climate and man in Africa' (South African Journal of Science, 1932) in which he concluded that there is strong evidence for a succession of dry and rainy climates in South Africa during the Pleistocene. Three years later, with his patronage, the Bureau of Archaeology was established, with Lowe as its first director.
Smuts earned a place in the literature of science by his speeches, his inaugural addresses to learned societies, and his many forewords to scientific works. The style he used is distinguished by its clearness of expression and the beauty of its prose.
In 1930 Smuts undertook an expedition to Lake Tanganyika, accompanied by Dr John Hutchinson*, Dr I.B. Pole Evans*, and Mrs Margaret Gillett* and her two sons. A detailed account of the expedition was published in Kew Bulletin (1931). Smuts usually wrote accounts of his collecting tours, including the plants he saw, and listing those he collected. One such account, on the vegetation of Schoemanskloof, Mpumalanga, which he visited in June 1932, was published in Kew Bulletin in 1933. In an appendix to the article Hutchinson provided a list of plants collected in Schoemanskloof and some collected earlier in the mountains of the eastern Transvaal. Smuts was a life-long friend of Pole Evans and they often collected plants together. Partly because of his prodigious memory, which enabled him to accumulate much botanical knowledge, he was regarded as a botanist of note despite his lack of botanical training. The species Digitaria smutsii (by S.M. Stent*) and Pteronia smutsii (by Hutchinson) were named in his honour. The specimens he collected went to Kew Gardens and the National Herbarium in Pretoria. Many of them were collected jointly with Mrs Gillett, or her son Jan.
In 1933 Smuts became minister of justice and deputy prime minister in the coalition government of General Herzog and again becamective in world politics. He became prime minister again in 1939, serving also as minister of defence and commander-in-chief during World War II. During the closing months of the war he was in San Francisco to take an active part in the establishment of the United Nations organisation. In May 1948 he lost his position in a general election.
Smuts received numerous honours, decorations and awards from various countries, including several honorary doctorates, among others from the University of the Cape of Good Hope (1915), theUniversity of the Witwatersrand (1922) and the University of Cape Town (1931). He served on the council of the University of the Cape of Good Hope during 1906-1907. He had a powerful intellect and was married to Sybella Margaretha Krige.