The delightfully potty Alasdair Gray published a book of prefaces in 2000 and the book, as ever, is as fabulous for its artwork and cheeky glosses as for its undoubted literary ambition (from Caedmon to Wilfred Owen). Gray is surely right that prefaces can be a sort of 'verbal doorstep to help readers leave the ground they usually walk on and allow them a glimpse of the interior.' You know that you have reached a new level of geekiness when you buy a different edition of a book you own just to get the author's new preface. (In my defence, I do think the author in question gave a good account of how he had changed his ground a little in the ten years since his first go at introducing the work...)
Thomas Merton took care over the prefaces he wrote for his books that were being translated for a new audience and many of these prefaces appear in a collection called 'Introductions East and West' and, later, '"Honourable Reader" Reflections on My Work'. These are useful pieces of writing for anyone who wants to see how this writer came to reflect on his work, sometimes many years after the book's initial publication. And because Merton's writing often appears in different places (sometimes with different titles), some of these prefaces were also published as stand-alone essays. One such is the preface he wrote to the Japanese edition of his lovely book of reflections, 'Thoughts in Solitude'. The book was published in English in 1958 though the thoughts contained in it were written a few years earlier in his first 'hermitage' - an old wood shed. The preface was written in 1966 and it is a good introduction to the way Merton's understanding of contemplation developed over that period.
Merton is keenly aware of his Japanese audience in writing this piece and his mode of expression owes a great deal to his understanding of Zen Buddhism, for example in his meditation on the kind of hearing in solitude that is a non-hearing:
The true unity of the solitary life is one in which there is no possible division. The true solitary does not seek himself, but loses himself. He forgets that there is number, in order to become all. Therefore, he is No (individual) Hearer. He is attuned to all the Hearing in the world, since he lives in silence.
and later on:
Where is silence? Where is solitude? Where is love? Ultimately, these cannot be found anywhere except in the ground of our own being. There, in the silent depths, there is no more distinction between the I and the Not-I.
He roots all of this understanding in distinctly Christian terms ('in Christ') but there can be no mistaking the contribution of Buddhist thought and practice to this preface. He does not refer explicitly to Zen, but sees the common language of contemplation as a way of communicating deep truth across cultures.