Isaac was the son of a Dissenter, Edward Maddox, stationer of London. He was orphaned at an early age, and brought up by an aunt who sent him to a charity school before apprenticing him to a pastry cook. However, assisted by an uncle, he resigned his apprenticeship and was tutored by Rev Hay, vicar of St Stephen Coleman Street. As a practising Dissenter, Maddox was given a grant from the Presbyterian Fund to study for the Dissenting ministry at the University of Edinburgh. Here he befriended John Horsley who later became the father of Samuel Horsley, who at that time was also destined for the Dissenting ministry. He was awarded MA in January 1722/3. Maddox returned to London early in 1723 and, along with John Horsley, promptly conformed to the Church of England, though he remained on friendly terms with Dissenters, notably Philip Doddridge of Northampton; and he conspicuously supported foreign Moravian Christians in the North American colonies. In 1740, foreign Protestants after a residence of seven years could become naturalized on swearing an oath of allegiance. Quakers were exempted this oath. In 1747, with Maddox’s support, the exemption was extended to Moravians. In his speech in the House of Lords, Maddox insisted that
it would be beneficial ‘if the British nation expresses itself in favour of the Moravian Church| Brethren; for whatever benefit England confers upon this ancient confessor Church must be an encouragement to all evangelical Christians throughout the world, to expect nothing but good from this country.’
Maddox supported numerous charities. In addition, he was president of the Small-pox Hospital in London, and a principle promoter of Worcester Infirmary, consulting Philip Doddridge who had taken a similar part in founding the County Infirmary at Northampton. He also promoted British industry, sinking a lot of money into supporting British fisheries. The breadth of his interest in charitable works is represented in the many charity sermons that were published.
Published works
Apart from numerous charity sermons, and plea for action against alcohol abuse, Maddox’s principal publication is his Vindication of the government, doctrine, and worship, of the Church of England, 1733, in which he ably defends the anti-Puritan position, criticising Daniel Neal’s History of the Puritans. His charity sermons include:
1743; The duty and advantages of encouraging public infirmariesthe London Infirmary, in Goodman’s-Fields, for the relief of sick and diseased manufacturers, and seamen in merchant-service, &c.
1748; The necessity of perseverance in well-doing; a sermonthe Worcester Infirmary.
1750; The expediency of preventive wisdomthe several hospitals of the city of London.
1752; A sermon preachedthe Hospital for the Small-pox, and for Inoculation.
1753; The wisdom and duty of preserving destitute infants.