When Nicholas Copernicus developed his model of a heliocentric universe, there were no fundamentally new discoveries or observations in the field of astronomy that led to his development (or, as he would insist, resurrection) of a radically different theory, nor were there any pressing issues -- save that of calendrical reform -- that might have instigated the search for a new paradigm. True, the old Ptolemaic model remained inaccurate despite centuries of attempted refinements by astronomers, but the Copernican system, with its perfectly circular orbits, was equally so, and required that one trade away a number of firmly entrenched assumptions in the bargain -- without offering anything to replace them. Why then, when it solved no practical problems, should such a theory manage to survive at all in the forum of ideas, let alone prove as tenacious as it did?

As there was no available empirical proof of Copernicus' heliocentric theory until stellar parallax (a change in the apparent angular distance of stars) could be measured, some 200 years after Copernicus' death, what position one took on the debate necessarily involved more than strictly rational evaluation of data. The astronomical discourse of the period instinctively drew on other discourses in what was necessarily a rhetorical battle. Thus the questions to be answered-while they certainly included those about how heliocentrism could work, and how well it might function as a tool for explaining and predicting the behavior of the physical world around us -- extended beyond the technical concerns of Renaissance astronomy, or even of physics, to the metaphysical. What did heliocentrism mean? Not only in the sense of what are the consequences of the sun being in the middle of the planets, but what does it mean semiotically? How can one read this, who can interpret this? What are the requisite preconditions and what are the consequences when one embraces a new model of the universe? What are the obstacles?

Gathered here, along with Copernicus himself and a curiously influential piece of poetry, is a sampling of that rather small number of individuals who published their views in support of his theory in the sixteenth and early seventeenth century.

There is a tendency to beatify those whose ideas anticipated our own -- Copernicus on what we now call our solar system, for example --- to attribute to them retroactively the status of genius-great minds at great moments in the evolution of science. When we do this we ignore something very important. Looking back at the history of science, we tend to see a singular path leading back through all the people who contributed to the discovery of the physical truth as we know it; a series of runners carrying the Olympic flame of rationality. This account reinforces the prevailing truths. But the perspective at the other end of this path is far different; nothing is clear and nothing is obvious, even when it seems so, least of all the true nature of physical reality as we now comfortably and confidently perceive it. There is, rather, a twisted maze of trails running ahead through the forest, and the reasons one chooses a direction may be entirely incorrect, even if the chosen path does prove to be fruitful. There is no real foundation for assuming those whom we remember and revere were singular intellectual giants, who towered over their now forgotten inferiors. The serendipity factor, the possibility that one might make the right choice for the "wrong" reasons -- reasons perhaps having nothing to do with the subject of inquiry-is at least as powerful as the genius factor (though neither may equal the persistence factor). The authors presented here are not at all of one mind, except in the matter of the most basic elements of the Copernican system. Nor are they of similar character, except in their willingness to maintain a controversial, even dangerous, position.

To evaluate the power of their individual arguments the reader needs to bring a range of critical skills to these readings-skills which you may have previously been taught to think of as mutually exclusive. The first requirement is that you understand completely the technical aspects of each text -- for example, what exactly is "right motion" or "circular motion?"-- and that you be able to judge the quality of these arguments. In this sense, reading these texts is not much different perhaps than solving a verbal problem in mathematics. But a verbal problem rarely mentions God, or makes analogies, or uses metaphors; rarely do you find any strong evidence of the author's basic beliefs, assumptions and prejudices about the world he lives in. (No one ever asked you to investigate the connotations of such a problem, and modem science would often like to ignore the existence of connotative meaning alongside the denotative.) The reader of these texts should be able to find such things embedded within these works, which were written at a time when science writers were not so careful about concealing their person behing the veil of objectivity so common in our modem world. You should not only be able to discover their views of the world, but through them come to understand the "unscientific" reasons why these authors embraced the Copernican system. You must read these texts with the same astuteness that you would bring to a poem; you must read this literature just as you would "Literature." You need to use, as it were, both halves of your brain: that part which extracts data and that part which notices style, which hears rhetoric.

Much of what you will find in these works will seem strange, even alien, and hence the inclusion of the bibliography. The intent of this book is to serve as an entryway, and to lend a specific perspective, to an investigation of early modem European culture. The Copernican Revolution did not occur merely through scholarly debate, it did not take place in cloistered universities. It took place in what seemed a rapidly changing world to those who inhabited it. Indeed, the very face of that world was changing, as Europeans explored and conquered ever more of it, thanks to the technological advances of shipbuilding, the compass, and the increasing sophistication in methods of dispensing death with gunpowder. A host of previously unknown social and economic issues also were presenting themselves. The Protestant reformation was having a profound effect upon peoples' lives, both personally and politically. The old balance between secular and religious authority had been upset, and monarchies had to evolve, reshape themselves, or risk extinction. Print technology and rising literacy caused an information explosion, with effects not unlike that of our own era. Ancient texts were being translated into the vernacular, and modem works were being printed at such a rate as to make effective censorship impossible. It is this ground upon which the Copernican idea takes root and comes to flourish, and it is this ground that must be assayed.'