To the Reader,

—tion completing "demonstration" from the previous page; yet I will say freely that I fear no man who claims to offer more reason for an opinion contrary to the one I assert. I believe whoever reads through this book will find that I am well aware of what opponents of all kinds might attempt to argue against it. Indeed, while we rely solely on reason in subjects of this nature, I suspect we may all have too much cause to mourn alongside the ingenious Girolamo Fracastoro original: "Fracastorius," a 16th-century Italian physician and scholar in his Epistle to Flaminius:

What shall I say that I, a miserable man, am doing, and what kind of life I lead? My mind is restless, searching in vain pursuit for Nature, who is always fleeing. When she has shown herself to me for just a moment, she suddenly transforms into a thousand faces—like Proteus a Greek sea god capable of changing shape at will—eluding and distressing her pursuer, who mourns the passing hours of old age and his wasted labor. original: "Quid dicam miserum me agere... cassumque laborem."