Similar to other works of extended scholarship, this work has taken far too long to write. Like many authors in a similar position, having completed the manuscript, I cannot understand why such a work has not yet been attempted, nor can I comprehend why it took me as long as it did. In writing the work, I sometimes feel like an apprentice illusionist seeing practiced conjurors seducing the unwary—their manipulations of reality appear so easy in the practiced hand, and I can only aspire to such apparent felicity. I have attempted this text with a goal that appears somewhat quaint and perhaps ill conceived: I wished to honor those Indian Buddhist masters who have constructed esoteric Buddhism in their own time. The quaintness stems from my dissent from the modern proclivity of writers to find fault when our forebears do not measure up to a conceptual architecture erected after their time. My ill-conception is that I have approached those of saintly aura and sought humanity where others seek holiness, having looked for the fragile edges of their personalities while the tradition affirms the impenetrable core of their personas. My compulsion to extend praise to these gentlemen proceeds despite our differences, for much that they did I have found disturbing or even, at times, dishonorable. Yet they produced a form of Buddhist praxis and identity that sought sanctity in a world unraveling before their eyes. So, perhaps as an extension of my American heritage, I have searched for the well-tamped earth of common ground, finding a meeting place on the horizon of history, one that displaces the sublime hierarchy of their preferred environment. Those of the Buddhist tradition will fault me for my critical, historical method, while those on some form of ideological crusade will castigate me for my lack of doctrinal rigor. I am at peace with either dissatisfaction.