Guarini spent his novitiate in Rome where he learned at first hand what Bernini and Borromini, now recognised as great masters of Baroque architecture, were doing, and their example presumably caused him to practice architecture, then considered as a mathematical art but not strictly a member of the Quadrivium, the mathematical division of the Liberal Arts, still supreme in the world of learning.
Guarini nagastos sa kanyang pagiging baguhan sa Roma kung saan siya unang natutunan sa kamay kung ano ang Bernini at Borromini, ngayon kinikilala bilang magaling na Masters ng Baroque architecture, ginagawa, at ang kanilang mga halimbawa marahil dulot sa kanya ng architecture, pagkatapos ay itinuturing bilang isang matematiko sining ngunit hindi mahigpit na isang miyembro ng Quadrivium, ang matematikal na dibisyon ng Liberal Arts, pa kataas-taasan sa buong mundo ng pag-aaral.