Research : about Hieronymus Bosch

Source:
referred to GOOGLE ' Hieronymus Bosch'
http://en.wikipedia.org/wiki/Hieronymus_Bosch
http://terms.naver.com/entry.nhn?docId=1102596

My Topic:

 How can we estimate Hieronymus Bosch as a surrealist painter or a holy picture painter?

What I hope to learn from this source:
 I want to find some information about Hieronymus Bosch such as explanations of his paintings,his styles and some comments and arguments from experts.

Notes:

1. Bosch produced several triptychs. Among his most famous is The Garden of Earthly Delights. This painting, for which the original title has not survived, depicts paradise with Adam and Eve and many wondrous animals on the left panel, the earthly delights with numerous nude figures and tremendous fruit and birds on the middle panel, and hell with depictions of fantastic punishments of the various types of sinners on the right panel.
2. 'the Hell panel' is painted in a comparatively sketchy manner which contrasts with the traditional Flemish style of paintings and conceals the brushwork. In this painting, and more powerfully in works such as his Temptation of St. Anthony, Bosch draws with his brush. Bosch also produced some of the first autonomous sketches in Northern Europe.
3. Bosch's paintings with their rough surfaces, so called impasto painting, differed from the tradition of the great Netherlandish painters of the end of the 15th, and beginning of the 16th centuries, who wished to hide the work done and so suggest their paintings as more nearly divine creations.
4. In the twentieth century, when changing artistic tastes made artists like Bosch more palatable to the European imagination, it was sometimes argued that Bosch’s art was inspired by heretical points of view (e.g., the ideas of the Cathars and putative Adamites) as well as by obscure hermetic practices. 
   
5.  Walter Gibson said about Bosch's paintings, "a world of dreams [and] nightmares in which forms seem to flicker and change before our eyes". Spaniard Felipe de Guevara wrote that Bosch was regarded merely as "the inventor of monsters and chimeras". The Dutch art historian Karel van Mander described Bosch’s work as comprising "wondrous and strange fantasies"; however, he concluded that the paintings are "often less pleasant than gruesome to look at". In recent decades, scholars have come to view Bosch's vision as less fantastic, and accepted that his art reflects the orthodox religious belief systems of his age. His depictions of sinful humanity and his conceptions of Heaven and Hell are now seen as consistent with those of late medieval didactic literature and sermons. Also, Bosch’s art was created to teach specific moral and spiritual truth.According to Dirk Bax, Bosch's paintings often represent visual translations of verbal metaphors and puns drawn from both biblical and folkloric sources.
6. However, the conflict of interpretations that his works still elicit raises profound questions about the nature of "ambiguity" in art of his period. Recent art historians emphasized his ironic tendencies. By adding irony to his morality arenas, Bosch offers the option of detachment, both from the real world and from the painted fantasy world. By doing so he could gain acceptance among both conservative and progressive viewers. Perhaps it was just this ambiguity that enabled the survival of a considerable part of this provocative work through five centuries of religious and political upheaval.

Final Thoughts:

I need more specific research for Hieronymus Bosch like why he painted, what ideas the painting have, what ideas the painter would convey.