Ronald Allison Kells Mason was born in Penrose, Auckland, on 10 January 1905, the son of Francis William Mason and his wife, Jessie Forbes Kells. His father, a perfume maker, died of an accidental overdose of opium in 1913 and he and his elder brother were sent to live with an aunt, Isabella Kells, in the south Waikato settlement of Lichfield. She taught the boys until 1915, when Mason returned for one year's primary schooling at Panmure before attending Auckland Grammar School from 1917 to 1922 (in 1919 and 1921 for only one term each year, apparently for economic reasons). He distinguished himself in English and Latin, and began writing verse. His translation of Horace's 'O fons Bandusiae' ('O fair Bandusian fountain') was evidently a class exercise done in the fifth form. In that same year he first encountered A. R. D. Fairburn, with whom he formed a close association over the next decade.
Soon after leaving school Mason took a position as a tutor in Latin, economics and civics at the University Coaching College, a private tutoring school where he was to be employed for six years. In 1923 he prepared a handwritten collection of poems which he named 'In the manner of men'. This was followed in 1924 by his first published volume, The beggar, which contained versions of many of the poems written during his school years. They are precocious, often morbid poems that reflect the highly rhetorical styles of the Victorian poets, but some are of lasting value. The beggar found almost no market in New Zealand. It did, however, reach the English anthologist and editor Harold Monro, who reprinted two of its poems in the 1924 issue of the Chapbook, and two more in the 1929 anthology Twentieth century poetry.
In 1925 Mason published a pamphlet, Penny broadsheet, containing five further poems. In 1926 he enrolled at Auckland University College, majoring in Latin and French. He studied full time that year and from 1928 to 1930, eventually graduating BA in 1939. Mason evidently continued to support himself by tutoring until near the end of his full-time studies. He continued to write poems, some of which were published in the local newspapers, the Sun and the Auckland Star, and wrote several short stories, published in Kiwi, the Phoenix and Tomorrow; He also drafted two novels, which remained unpublished.
After completing his full-time studies he worked for a season in Lichfield as a harvester before returning to Auckland to a variety of labouring jobs, and to close association with friends active at the university. In the first months of 1931 he travelled to Tonga and Samoa to study the conditions on those islands, and particularly the circumstances of the Mau uprising in Samoa. This trip he described as beginning his disillusionment with New Zealand nationalism, which was to culminate in 1947 with the publication of the pamphlet Frontier forsaken: an outline history of the Cook Islands.
Between 1931 and 1933 Mason contributed regularly to Kiwi and to the Phoenix, a student publication printed by Bob Lowry at Auckland University College. The first two issues in 1932, edited by James Bertram, emphasised cultural and aesthetic issues. Mason assumed the editorship in 1933; under him the third and fourth issues had a more directly political emphasis, and the magazine's controversial nature made it the focus for attack from the conservative press.
By this time Mason's interests had clearly moved from the poetic to the political. Although he was to publish three books of verse in the next 10 years, all but about 12 of the poems eventually collected under his name had been written by 1933. No new thing (1934) contained 25 poems from 1924 to 1929. The book was printed by Lowry at the Unicorn Press, but problems with binding meant that only a few copies were issued for sale. Mason retained his business association with Unicorn for a short time, but the Caxton Press published his poems from then on. End of day (1936) printed five new poems, and a further five were included in Caxton's Recent poems (1941). This dark will lighten: selected poems, 1923–41 was Mason's first substantial selection of his work and the first to make it widely available. In it he stripped down the typography and punctuation, making increasing use of the hanging indent that he had first used a decade before, and paring down the rhetorical diction and flourishes of some of the earlier poems.
Mason's writing after the mid 1930s was mainly political journalism and didactic plays for the stage, radio and dance theatre. At least 10 plays were written; two were published separately, Squire speaks in 1938 and China: script…for a dance-drama by Margaret Barr in 1943. He wrote political and social commentaries extensively, using both his own name and 'PWD'. He published in Tomorrow, the Workers' Weekly and the People's Voice, the communist weekly newspaper. When this was banned by the government in 1941, Mason edited, printed and published its successor, In Print. He was briefly the publisher of the revived People's Voice in 1943–44 and then publisher of Challenge, the weekly journal of the Auckland District Labourers' Union. He is also recorded in 1950 as the publisher of a union paper, Congress News, the journal of the New Zealand Trade Union Congress. He made another trip to the Pacific islands prior to the publication of Frontier forsaken in 1947. In the years immediately after the war he was a strong advocate of the establishment of a national theatre.
Ill health forced Mason into semi-retirement in 1956, though for several years he continued to work a little as a landscape gardener. In that year he welcomed a troupe of the Classical Theatre of China to Auckland, and in 1957 he was a member of a New Zealand delegation invited to the People's Republic of China.
In 1962 Pegasus published his Collected poems. The book drew together all the published and unpublished poems he wished to retain, while the last of the earlier poems were revised for republication. In the same year he held the Robert Burns Fellowship at the University of Otago. Three poems were printed in the students' association's Review and 'Strait is the gate', a play with strong Otago themes, was performed and later recorded for radio. Also that year, on 27 August, he married his long-time companion Dorothea Mary Beyda (known by her maiden name of Dorothea Mould). They remained in Dunedin until 1965, when they returned to Auckland, living in Takapuna where Mason taught part time. In 1969–70 the New Zealand Literary Fund Advisory Committee discussed a recommendation that a pension be paid to him in recognition of his achievements, but he died on 13 July 1971 before this could be done. He was survived by his wife.
In his own lifetime Mason was respected for his commitment to the trade union movement, and for his dedication to the principles of Marxism as a political philosophy. Although it is as a poet that he is deservedly best remembered, the ethical and existential questions that the poems confront seem to have been answered for Mason by his espousal of Marxist principles, and the transferral of energy from poetry to politics in the mid 1930s was a part of this process. Mason's poetry was humanistic and sceptical, concerning itself with the quest for purpose in a universe which appeared to be essentially mechanistic or godless. The earlier poems are frequently concerned with a sense of despairing mortality, and a feeling that the poet is the plaything of history. The later poetry, often focusing on the figure of a secular suffering Jesus, who is human rather than divine, poses dramatised questions about the consequences of ethical choice and the problems faced by the good man in a morally indifferent society.
Stylistically and thematically much of Mason's poetry marks him as an inheritor of the Victorian tradition, although equally he was influenced by the Georgian practices of his time. His work stands somewhat apart from the more overtly nationalistic writings of his contemporaries, though he shared with them a sense of romantic alienation and a view of poetry as primarily a morally instructive art. His poems from The beggar on also mark the beginnings of serious modern poetry in New Zealand, and his best poems remain numbered among the finest in New Zealand literature.