Parshat Tazria-Metzorah has rules that pertain to states of purity and impurity. In this discussion, Rav Aron Liechtenstein places these laws in context, saying that the Jewish approach to purity and impurity occupies the space between a nihlistic perception of the universe and one that sees purity and impurity as an inherent part of the universe's structure:
The full text can be found here.
The Jewish approach in this regard differs from the two other prevalent attitudes to this issue. The magical approach claims that there are in fact forces of sanctity and impurity inherent in the world, but they are primordial, embedded within the natural order. There are demons, evil spirits and the like, but man does not and cannot bring them into existence; they emerged together with the rest of creation. The scientific approach, by contrast, maintains that no forces of sanctity or impurity exist in the world whatsoever. No object can be seen as more sacred then the next, no given place can be considered holier than the next, and no quality of impurity can be attributed to corpses or anything else. Simply put, science outright rejects all these concepts.
Judaism disputes both positions. On the one hand, it rejects the scientific approach and insists upon the existence of sacred and profane, purity and impurity. Even further, it believes in a hierarchy of levels of sanctity and purity. On the other hand, it disputes the magical approach and sees all sanctity and impurity as emanating from man, not from nature. Man creates sanctity - he writes Torah scrolls and tefillin (and only with the proper intention in mind), he designates an animal as sacred for the purposes of sacrifices, and he even infuses specific periods of time with sanctity.