Given the following context:

Little is known for certain of the life of Hieronymus Bosch or of the commissions or influences that may have formed the basis for the iconography of his work. His birthdate, education and patrons remain unknown. There is no surviving record of Bosch's thoughts or evidence as to what attracted and inspired him to such an individual mode of expression. Through the centuries art historians have struggled to resolve this question yet conclusions remain fragmentary at best. Scholars have debated Bosch's iconography more extensively than that of any other Netherlandish artist. His works are generally regarded as enigmatic, leading some to speculate that their content refers to contemporaneous esoteric knowledge since lost to history.
Although Bosch's career flourished during the High Renaissance, he lived in an area where the beliefs of the medieval Church still held moral authority. He would have been familiar with some of the new forms of expression, especially those in Southern Europe, although it is difficult to attribute with certainty which artists, writers and conventions had a bearing on his work.José de Sigüenza is credited with the first extensive critique of The Garden of Earthly Delights, in his 1605 History of the Order of St. Jerome. He argued against dismissing the painting as either heretical or merely absurd, commenting that the panels "are a satirical comment on the shame and sinfulness of mankind". The art historian Carl Justi observed that the left and center panels are drenched in tropical and oceanic atmosphere, and concluded that Bosch was inspired by "the news of recently discovered Atlantis and by drawings of its tropical scenery, just as Columbus himself, when approaching terra firma, thought that the place he had found at the mouth of the Orinoco was the site of the Earthly Paradise". The period in which the triptych was created was a time of adventure and discovery, when tales and trophies from the New World sparked the imagination of poets, painters and writers. Although the triptych...

answer the following question:

What is the first name of the person whose thoughts on what inspired him to such an individual mode of expression art historians have struggled with? 

Hieronymus