That is supernatural, whatever it be, that is either not in the chain of natural cause and effect, or which acts on the chain of cause and effect, in nature, from without the chain. [Horace Bushnell, "Nature and the Supernatural," 1858]
That which is supernatural is above nature ; that which is preternatural or extra-natural is outside of nature ; that which is unnatural is contrary to nature, but not necessarily impossible. [Century Dictionary]