One of the most striking biblical images is Jacob's ladder as revealed to him in a dream at Bethel. This passage promised that communication between heaven and earth was possible, articulated the links between the supercelestial and the terrestrial levels of the cosmos, and suggested that communication between heaven and earth could be reciprocal. The question that faced natural philosophers interested in bridging the gap between celestial and terrestrial was how to build and ascend such a ladder. John Dee, along with many of his contemporaries, searched a variety of authoritative treatises for information on how to ascend “Jacob's ladder” to learn the secrets of the cosmos, and then descend to share that information with a waiting world. Dee's library furnished him with the tools and materials that served as a foundation for his conversations with angels, and they provide us with the intellectual context for what he sought to accomplish.

Building a ladder that linked heaven and earth promised a natural philosopher like Dee the intellectual attainment of certain knowledge, as well as the moral achievement of spiritual salvation. Dee had been striving for both long before he became involved in his angel conversations. From his youth Dee attended lectures at the finest universities in Europe, discussed natural philosophy and theology with English and European scholars of high repute, and collected the greatest library in England. He established networks of patronage to support his work and family, and regularly, though not prolifically, published original treatises on natural philosophy. By 1581, however, none of these activities had provided him with the certain knowledge of the natural world or the moral salvation vital to his success in natural philosophy.