A businessman, Arias attended schools in Panama, Jamaica, and the United States.
Tomás Arias's eloquence and talent as a public speaker won him the designation of diplomat representing the Isthmus of Panama.
During his political career he held several posts: Treasury administrator, Departmental Assembly deputy (1882), representative to the Colombian Congress, senator (1888-1892), government secretary (1893-1900), foreign relations minister, chairman of the National Assembly (1906), minister of Panama in Mexico, consul, and first President of the Republic of Panama (1903-1904).
Arias, along with José Agustín Arango, defended the Hay–Bunau-Varilla Treaty because he was convinced that it was the only guarantee of the possible construction of the Panama Canal.
(1999) • Mellander, Gustavo A., The United States in Panamanian Politics: The Intriguing Formative Years."