Felix Wilfrid Arden was born on 20th April 1910, in Singapore, then a British Colony within the Straits Settlements. His father was Stanley Arden, a rubber planter and horticulturalist. Felix Arden's mother, Winifred Arden, was from a Quaker family and was a devout Christian throughout her life. Felix, a brilliant student, was sent as a boarder to St. Edward King and Martyr School in Oxford. It was there that he matriculated to University at the age of fifteen. The family emigrated to Adelaide for reasons of his father's health. There Felix entered the Faculty of Medicine at the age of fifteen years, one of the youngest medical students in the history of medicine in Australia. He graduated MB BS from the University of Adelaide in 1931, aged 21 years. In 1932 he enrolled for the research degree of Doctor of Medicine at Adelaide University. Using a flame-photometer to measure serum and urinary sodium and potassium concentrations, he embarked on a programme of research into sodium metabolism. A milestone paper entitled The Excretion of Salt by the Human Kidney was published in 1934, and another, using himself as an experimental subject, on the effects of potassium over dosage and its secondary effects upon the subjective sense of thirst modified by endogenous ion receptors. Such were to presage the development and later worldwide use of oral rehydration solutions. In 1936, as a young clinician and published medical scientist, Felix Arden was appointed Outpatients Registrar at the Adelaide Children's Hospital. It was there that he met and married a young trainee nurse, Dorothy Ray.

In 1937, at the age of 27 years, he had already established a reputation for leadership, maturity and integrity and was appointed Medical Superintendent at the Adelaide Children's Hospital. In 1938 he was appointed as the Medical Superintendent to the Hospital for Sick Children in Brisbane, renamed The Royal Children's Hospital in 1968. Brisbane and Queensland were to become his home and where, over the ensuing half century, his name was to become a household word. He served as Medical Superintendent at the Children's Hospital in Brisbane until 1946, living with his family in the Superintendent's on-site house in the Hospital during the difficult period of acute doctor-shortage in the years of World War II. Felix Arden was a fine paediatric surgeon and a superlative diagnostician. In the pre-antibiotic era, he performed all types of surgery and was particularly noted for abdominal surgery of infants and young children, for ENT surgery and specifically for his work on the repair of cleft palate. He established an international reputation both for the syndrome of intrapartum rupture of the neonatal liver and for its treatment; and for his contributions to the understanding of the pathology of and clinical management of acute laryngotracheobronchitis. He published a case series of both fatal and salvaged victims of acute laryngotracheobronchitis from his own beds at The Hospital for Sick Children in Brisbane. Arden's descriptions of the symptoms and pre-morbid signs of intrapartum rupture of the liver, in neonates was the first clinical series of a syndrome which had hitherto been described only at autopsy. His description of this syndrome and his advocacy to obstetricians, general practitioners and paediatricians of the potential of hepatic rupture particularly during the birth of very large babies (over 4.5kg) led, for the first time, to potential salvage by massive transfusion and surgery.

The exceptional quality of his clinical work and his perceptive publications led to four of them being published, audited and annotated in the International Year Book of Paediatrics. Felix Arden was at the epicentre of the controversies that surrounded the new and radical treatments proposed for poliomyelitis victims by Sister Elizabeth Kenny. In retrospect, those events of the years 1934 to 1946 were one of the defining periods in the history of Australian medicine in the sense that for the first time the medical model of a major and important clinical therapy was challenged by someone not a doctor. Felix Arden was Medical Superintendent at The Hospital for Sick Children in Brisbane at that time when the parents of children admitted with poliomyelitis had to be asked whether they wanted 'their children to receive the orthodox treatment or the Sister Kenny treatment?' So bitter was the controversy that a Royal Commission was established to investigate Kenny's claims. Felix Arden, the Medical Superintendent of the Hospital at the epicentre of this controversy, together with Dr Aubrey Pye, his superior and Superintendent of the Brisbane General Hospital, maintained an objective dignity at the epicentre of that storm. The Royal Commission published its findings on January 6th 1938 and found that Sister Kenny's claims were unproven. However, Dr Felix Arden, together with five other clinicians (Drs Nye, Pye, Fryberg, Lee and Professor Wilkinson) found that in a significant number of cases, rehabilitation of poliomyelitis victims had indeed been advanced by the Kenny methods of treatment – 'it is our belief that she has made an important contribution'. By 1942 widespread acceptance of the Kenny treatment of 'heat and passive physiotherapy' had replaced the universal methods of splints and enforced inactivity for the management of acute poliomyelitis cases. Arden's stature in those events stands tall. He lived to see the introduction of the term 'evidence-based medicine', a paradigm which he had always followed even in an era of dogmatic and paternalistic dominance by the medical profession.

Arden was the Hospital Superintendent in Brisbane not only during the poliomyelitis epidemics but also during the epidemics of diphtheria and typhoid, which would rapidly fill the beds of children's hospitals throughout Australia. He was the Medical Superintendent in 1944 at the time of the first use of penicillin for sick children in Queensland, supervising the administration of precious aliquots of the drug, now known to be less than 10,000 units, obtained informally from the US Army Medical Corps, then part of the huge World War II deployment garrison based in Brisbane. Felix had special skills with young children, especially neonates and infants. He consulted extensively on the most difficult cases delivered by specialist obstetricians at the Brisbane Women's Hospital. He saw the introduction of the new discovery of the Rhesus factor (1940) and the clinical endeavours to both treat and reduce Rhesus disease in Australia from that time. Tragically, he and Dorothy Arden lost three infants (two stillborn and one neonatal death) from Rhesus disease, before its treatment had been developed.

Felix Arden entered private practice in 1946, and remained as the Senior Consultant at The Royal Children's Hospital in Brisbane until 1970. Until 1975 he was regarded as one of the best clinical opinions in paediatrics in Queensland. Many doctors brought their own children to him, perhaps the highest accolade of peer review, during the last thirty years of his active clinical life. Arden's contribution as a pioneer of the infant specialty of paediatric oncology began early in 1963 with the establishment of the first children leukaemia clinic in Queensland. Dr Arden was one of twenty-one Australian paediatricians who collaborated in the pioneering study of cyclic anticancer therapy which was completed in September 1966. The results were published in a classic paper in The Lancet in 1968. Felix Arden's influence on paediatric education was most significant. He was appointed University Lecturer in Paediatrics to medical students at the Hospital for Sick Children and taught the first cohort of students undertaking paediatric studies (from 1939) at the newly established Medical School at the University of Queensland. He was an influential member of the Advisory Committee on Paediatrics established by the University of Queensland in 1946, and taught two generations of graduating Queensland doctors until his final retirement from paediatrics teaching in 1975. He served on the Queensland State Council of the British Medical Association for ten years (1942-1951), including the demanding post-war years when many hundreds of medical servicemen were re-entering the profession; and when many of those who had their studies interrupted re-entered, often as more senior colleagues, the life of undergraduate medical studies. Felix Arden was renowned for his dignity and integrity and his election as President of the Queensland Branch of the British Medical Association in 1956 was unanimous. He served also on the Medical Board of Queensland and on numerous hospital, British Medical Association and Queensland State Government advisory committees.

One of his greatest legacies is his record as a co founder of the collegiate Division of Paediatrics and Child Health in The Royal Australasian College of Physicians. His role in this body was his advocacy, as part of the seven-person informal meeting which met in Lennons Hotel in Brisbane in 1949, to plan the formation of the Australian Paediatric Association and was a member of its first Committee when it was established in 1950. He served as President in 1974. From his base in the Australian Paediatric Association and its successor, the Australian College of Paediatrics, he was influential in advocacy with personal representations to the World President of Rotary International, in the 1980s, in advocating the potential input of Rotary into poliomyelitis immunisation campaigns. It was a point of particular fulfilment to him when Australia (as part of the south-west Pacific Region) was declared poliomyelitis-free by the World Health Organisation in October 2000. His personal life was one of devout service to his church. An uncompromising Christian, he was one of the Australian leaders of the Friends of Vellore, an influential body which raised funds and provided resources and doctors for the Christian Medical College at Vellore, India. He maintained a lifelong passion for horticulture, and established a small pine plantation on his property at Woodridge, then in the bush in an outer Brisbane suburb. He bred chrysanthemums and one particularly beautiful new cultivar (pale mauve with recurved petals) was registered and named after his wife, Dorothy. He was an over-enthusiastic jam-maker. He was President of the Clayfield Bowls Club in 1956 and was the lead bowler in the Champion Triples in 1996. In 1999, at the age of 89 years, Dr Arden was the lead bowler in the winning Open Championship Fours at the Clayfield Bowls Club, Brisbane, where he had been an esteemed member for four decades. Dorothy (Dot) Arden died in 1979, and in December 1980 Felix married Joy Richards, a widow and former close friend of his family for many decades. Many honours were conferred on him, as affirmation of his exceptional role and influence in both the collegiate and clinical world of paediatrics and for his work for the promotion of the welfare of children. He was awarded the rare honour of Honorary Doctorate of Medicine at the University of Queensland for his contributions to paediatrics. He was created a Fellow of the Royal Australasian College of Physicians in 1972, Queensland Father of the Year in 1983 and created a Commander in the Order of the British Empire (CBE) in 1984. His place in the chronology and heritage of paediatrics and child health in Australia is most significant.