Following on the last article I shared from Michael Shermer, a slightly older article from a skeptic with a slightly more philosophical bent, Michael Sherlock. Michael (the second one) writes primarily on issues having to do with skepticism, secularism and free speech.
I mentioned at the end of this student talk, I asked them the question, If this were really accomplished by magic instead of trickery, how could you tell? And turned out you never could. Where "real" magic is concerned the best you can ever get to is "I don't know".
At the root of the problem is the fact that magic and supernatural are not well defined terms. They tend to be placeholders for the as-yet-unexplained. In Magic and the Supernatural, Michael Sherlock explains:
It gets quite dense quite quickly after that, but Sherlock is a very articulate exponent of these ideas.