Marsilio Ficino (Latin name: Marsilius Ficinus) (Italian pronunciation: [marˈsiljo fiˈtʃino]; October 19, 1433 – October 1, 1499) was one of the most influential humanist philosophers of the early Italian Renaissance, an astrologer, a reviver of Neoplatonism who was in touch with every major academic thinker and writer of his day, and the first translator of Plato's complete extant works into Latin. His Florentine Academy, an attempt to revive Plato's school, had enormous influence on the direction and tenor of the Italian Renaissance and the development of European philosophy.

Ficino was born at Figline Valdarno. His father was a physician under the patronage of Cosimo de' Medici, who took the young man into his household and became the lifelong patron of Marsilio, who was made tutor to his grandson, Lorenzo de' Medici. Giovanni Pico della Mirandola, the Italian humanist philosopher and scholar was another of his students.

During the sessions at Florence of the Council of Ferrara-Florence in 1438–1445, during the failed attempts to heal the schism of the Orthodox and Catholic churches, Cosimo de' Medici and his intellectual circle had made acquaintance with the Neoplatonic philosopher George Gemistos Plethon, whose discourses upon Plato and the Alexandrian mystics so fascinated the learned society of Florence that they named him the second Plato. In 1459 John Argyropoulos was lecturing on Greek language and literature at Florence, and Ficino became his pupil.

Giordano Bruno (1548 – February 17, 1600), (Latin: Iordanus Brunus Nolanus) born Filippo Bruno, was an Italian Dominican friar, philosopher, mathematician and astronomer. His cosmological theories went beyond the Copernican model in proposing that the Sun was essentially a star, and moreover, that the universe contained an infinite number of inhabited worlds populated by other intelligent beings. He was burned at the stake by civil authorities in 1600 after the Roman Inquisition found him guilty of heresy for his pantheism and turned him over to the state, which at that time considered heresy illegal. After his death he gained considerable fame, particularly among 19th- and early 20th-century commentators who, focusing on his astronomical beliefs, regarded him as a martyr for free thought and modern scientific ideas.

Some assessments suggest that Bruno's ideas about the universe played a smaller role in his trial than his pantheist beliefs, which differed from the interpretations and scope of God held by the Catholic Church. In addition to his cosmological writings, Bruno also wrote extensively on the art of memory, a loosely organized group of mnemonic techniques and principles. The work of Frances Yates, especially influential in anglophone scholarship, argues that Bruno was deeply influenced by the astronomy found in Arab astrology, Neoplatonism and Renaissance Hermeticism. Other recent studies of Bruno have focused on his qualitative approach to mathematics and his application of the spatial paradigms of geometry to language.