Dictionary of National Biography, 1885-1900/M'Mahon, Thomas O'Brien
M'MAHON, THOMAS O'BRIEN (fl. 1777), miscellaneous writer, was a native of Tipperary and a Roman catholic. He published at London in 1774 'An Essay on the Depravity and Corruption of Human Nature,' 12mo, which was followed in 1776 by a supplement, called 'Man's Capricious, Petulant, and Tyrannical Conduct towards the Irrational and Inanimate part of the Creation inquired into and explained. His opinions were ridiculed in the 'Critical,' 'Monthly,' and 'London' reviews, and he retorted at great length in a pamphlet entitled 'The Candour and Good-nature of Englishmen in their deliberate, cautious, and charitable way of Characterising the Customs, Manners, Constitution, and Religion of Neighbouring Nations, of which their own Authors are ever produced as vouchers,' 8vo, London, 1777 (reprinted at Dublin in 1792 as 'Remarks on the English and Irish Nations').
[M'Mahon's Works; Watt's Bibl. Brit.]