Magic, although often associated with the Neopagan movement, is really not a reliable identifying feature of a religion falling under the Pagan/Heathen umbrella. One doesn’t have to be Pagan to be a witch or magician—historically speaking, the best known magi from Medieval Europe were Christian or Jewish, or even sometimes Muslim. Still, I think a lot of folks first discovered Neopaganism through magic of one sort of another, whether it be the occult section of their local library or the simple enchantment of a misty wood at dawn.
Definitions of what magic “is” can get pretty tricky. The levels of acceptability for magic have fluctuated throughout the ages depending on period and culture. Going back to the Greek world, magic was differentiated into two types, one acceptable and one not. In general, anything performed publicly or the light of day was fine. But a nocturnal rite, carried out in secret was a punishable offense. Therefore, things like divination, when performed in the city temple, were perfectly normal; but if one tried to do such a thing privately (see Alcibiades and the Eleusinian mysteries as an example), it was a different story.
Medieval Europe was a hotbed for magical practices, though many more of them were now carried out in secret. Unlike the Greco-Roman world, there was now one God and for the most part, one religion throughout Europe and the Mediterranean. Christianity and the church played a large role in determining which forms of magic were acceptable and which got tossed in to the pile labeled “witchcraft.”
Astrology is an interesting case study: officially, the church condemned all practice of divination. However, astrology escaped this classification for a few reasons. One, the heavens were thought to be the work of god, and it was a reasonable leap to draw the connection between god’s will in the heavens and that on earth. Another is that it served as a valuable socio-political tool. For instance, both the courts of Burgundy and France in the 15th c. resorted to magicians and diviners for various purposes—and indeed, a public accusation of sorcery leveled at a political opponent was a very potent weapon. In addition, acceptance of astrology blocked some of the interest in other less savory practices. Lastly, because astrology and astronomy were so closely linked, the presence of astrology in the universities of the period lent it some legitimacy. More generally, if a particular practice were popular in a royal court, it would have a blind eye turned to it by the church.
The major thing that has changed regarding magic through the ages is that today it’s becoming much more culturally acceptable, whereas in the ancient world, magic, by definition, was something that was not sanctioned by the state religion. While there is still secrecy surround the specific techniques employed, it is much more possible to find others with a shared interest and openly discuss its existence in our culture. It is now possible to be an “out” witch and not face immediate arrest and trial for one’s beliefs and practices.
I do in fact like Crowley’s definition as magic being the art and science of causing change in accordance with will. It’s beautiful, simple, and captures the essence of the practice as well as anything. But it is an emic account, meaningful to those within a magician’s subculture. To try to find an etic perspective is difficult, but I believe Marcel Mauss’ theory of magic works fairly well from an anthropological frame of reference. He considers magic analogous to both religion and science, but still remaining a distinct social phenomena with its own set of rules and goals. More often than that, though, I consider magic to be to religion as technology is to science: the application of faith, putting one’s spirituality into practice in the physical world.
Magic is certainly a wonderful complement to Druidic paths, but I honestly believe that the discipline, connectedness and responsibility that can be inspired by a magical practice makes a good addition to just about any faith. Still, every person must decide for themselves whether or not it’s suitable for them on their journey, though I hope everyone gets a chance to experience true and clear magic at least once in their lives.