If you're not familiar with the name, Meister Eckhart was a 13th/14th Century German Dominican cleric, of great intellect, wide study, and personal force. According to Blakney, Eckhart seems to have been familiar with a broad range of spiritual knowledge, from the classic thinkers of ancient Greece, to Lao Tzu in China and the Upanishads in India, and he brought these threads together in his writings and sermons. Unfortunately for him, he tended to "riff" in his sermons, coming up with spontaneous "uncovered truths" which blurred the line of heresy. Also unfortunate was that he came from a region rife with "mystical heresies", and soon became the target of the Franciscans, who eventually succeeded in bringing him before the Inquisition in his 60's, leading to his eventual (although undocumented) demise.
Eckhart's ego certainly did not help in his problems with the Inquisition. The last sections of this book deal with his defense to various charges made against either his written teachings or the reports of his various sermons ... here's a sampling of how he framed his defense: "[Careful studies of his words] reveal the intellectual weakness or malice of my opponents, rather than their manifest blasphemy or even heresy ..." Yep, nothing like calling your accusers stupid and evil to grease the skids of justice!
Blakney's Meister Eckhart presents several of his early works, a couple of dozen "sermons", bits and pieces of fragmentary works and "legends" about him, and the text of his 1326 "Defense" against the Inquisition. It provides a very interesting look at a man's vision of the Divine which strongly effected many movements that followed.
Amazon's got this at its $15.00 cover price, but you can pick one up for less with their new/used vendors. While I recommend this, I recommend it specifically to those with an interest in Western mysticism and "Church History" (and I was, after all, a Religion Major, so have a background suitable to processing this stuff without too much boredom creeping in). If you're looking at a way of injecting a mystical awareness into a very Christian structure (needless to say, I would have much preferred an outright heretical version!), this might also be of interest.