I was just reading this transcript of a lecture on alchemy given by the wild man of ethno-botany Terence McKenna and thought I'd drop this quote into your sunday tea:

"We also are living in the twilight of a great empire, and I don't particularly mean the American empire, I mean the empire of European thinking created in the wake of the Protestant Reformation and the rise of modern industrialism, the empire, in short of science. Science has exhausted itself and become mere techni. It's still able to perform its magical tricks, but it has no claim on a metaphysic with any meaning because the program of rational understanding that was pursued by science has pushed so deeply into the phenomenon of nature that the internal contradictions of the method are now exposed for all to see. In discussing alchemy especially we will meet with the concept of the coincidencia apositorum-the union of opposites. This is an idea that is completely alien to science. It's the idea that nothing can be understood unless it is simultaneously viewed as both being what it is and what it is not and in alchemical symbolism we will meet again and again symbolical expression of the coincidencia apositorum. It may be in the form of a hermaphrodite, it may be in the form of the union of soul and Luna, it may be in the form of the union of Mercury with lead, or with sulphur, in other words alchemical thinking is thinking that is always antithetical, always holds the possibility of by a mere shift of perspective its opposite premise will gain power and come into focus."