It was in the process of forming a new and powerful friendship that Tone's ideas (and indeed personality) grew to maturity. In the public gallery of the Irish House of Commons during the July 1790 sittings, Tone met and befriended Thomas Russell. Several years his junior, Russell was a foil to Tone in every way. He was everything Tone was not. An officer on half-pay, he had recently seen active military service in India and had a commanding military presence, his huge dark eyes and thick black hair offset by highly refined features. His good looks and ‘stately’ bearing commanded attention from men and women alike. Even the order for his arrest in 1803 is complimentary: ‘a tall, handsome man’, of ‘dark complexion, aquiline nose, large black eyes, with heavy eye-brows, good teeth, full-chested, walking generally fast and upright, and having a military appearance … speaking fluently, with a clear distinct voice, and having a good address’.Mary Ann McCracken – an early feminist and one of the few women to have a significant impact on the United Irishmen – remembered Russell as: ‘A model of manly beauty …, more than six feet high’, ‘majestic [in] stature’ and ‘martial in his gait and demeanour … the classic contour of his finely formed head, the expression of almost infantine sweetness which characterized his smile, and the benevolence that beamed in his fine countenance, seemed to mark him out as one, who was destined to be the ornament, grace and blessing of private life’.

Deeply religious and introspective, Russell's seriousness and self-flagellation for his own failings prompted the friendly raillery of the more flippant and gregarious Tone. In contrast to the male companionship of Tone's education, Russell (youngest of five children by many years) had been educated at home by his father, a former clerical student turned soldier. Russell emerged with a good knowledge of the classics, science and modern languages, but most of all of scripture and morals – unlike Tone, whose knowledge of the Bible was so inadequate as to suggest that he had neglected scripture classes at Trinity as he did so many others.