Arthur James Cook, the son of a soldier, was born in Wookey, Somerset, in 1883. Cook was raised as a Baptist and by the age of sixteen he acquired the title of "the boy preacher". A devout teetotaller he was attracted to Socialism as he saw it as a natural expression of his Christianity.
In 1899 Cook moved to Merthyr Tydfil to seek employment in the coal mines. He joined the Independent Labour Party (ILP) and became an active member of the National Union of Mineworkers. In 1910 he played a leading role in the Cambrian mining dispute that resulted in the Tonypandy Riots.
According to Christopher Farman, Cook was: "A wild but hypnotic orator, whose revolutionary fervour was flavoured with the religious revivalism of his days as a Baptist lay preacher, his pithead meetings drew crowds even greater than those which had listened to Keir Hardie. Cook was a mirror-image of every miner's frustrations and yearnings. In private conversation often in tears himself when describing the privations of the miners, Cook was able to produce an astonishing effect on an audience." Farman described how Lord Sankey "once stood at the back of a crowded miners' meeting to hear Cook speak. Within fifteen minutes half the audience was in tears and Sankey admitted to having the greatest difficulty in restraining himself from weeping."
Beatrice Webb, one of the leaders of the Fabian Society, was not so kind in her description of Cook: "He is a loosely built ugly-featured man - looks low-caste - not at all the skilled artisan type, more the agricultural labourer. He is oddly remarkable in appearance because of his excitability of gesture, mobility of expression in his large-lipped mouth, glittering china-blue eyes, set close together in a narrow head with lanky yellow hair - altogether a man you watch with a certain admiring curiosity ... it is clear that he has no intellect and not much intelligence - he is a quivering mass of emotions, a mediumistic magnetic sort of creature - not without personal attractiveness - an inspired idiot, drunk with his own words, dominated by his own slogans. I doubt whether he even knows what he is going to say or what he has just said."
Cook was a strong advocate of industrial action and was the co-author of a well-known Syndicalist pamphlet, The Miners' Next Step (1912). It stated: "That the organisation shall engage in political action, both local and national, on the basis of complete independence of, and hostility to all capitalist parties, with an avowed policy of wresting whatever advantage it can for the working class."
A. J. Cook was also a supporter of workers' control of industry: "Today the shareholders own and rule the coalfields. They own and rule them mainly through paid officials. The men who work in the mine are surely as competent to elect these, as shareholders who may never have seen a colliery. To have a vote in determining who shall be your fireman, manager, inspector, etc., is to have a vote in determining the conditions which shall rule your working life. On that vote will depend in a large measure your safety of life and limb, of your freedom from oppression by petty bosses, and would give you an intelligent interest in, and control over your conditions of work. To vote for a man to represent you in Parliament, to make rules for, and assist in appointing officials to rule you, is a different proposition altogether."
Cook was opposed to Britain's involvement in the First World War and took part in the campaign against conscription. He joined the