Michael Quinion of World Wide Words highlighted the word Grimoire in issue 872 of his newsletter this way:

2. Grimoire
A grimoire is a book of magic that may contain spells, conjurations, instructions for divination and the construction of amulets, and other secret knowledge of a supernatural kind. The examples include such famous works as the Sixth and Seventh Books of Moses, The Book of St Cyprian, The Key of Solomon and The Sacred Magic of Abramelin the Mage.
The word is French, in the same sense. It began to appear in French-English dictionaries early in the nineteenth century but became more widely known in the 1850s. In French, it was a medieval modification of grammaire, a book of grammar, by which was meant Latin grammar, since at the time there was no other kind. It derives from the Latin grammatica, the study of literature in general, which by the Middle Ages had come to mean knowledge of Latin.
The shift from book of grammar to book of magic isn’t as weird as it might seem. Few among the ordinary people in those times could read or write. For superstitious minds books were troubling objects. Who knew what awful information was locked up in them? For many people grammar meant the same thing as learning, and everybody knew that learning included astrology and other occult arts.

Grammar as magic

I love the idea of grammar as magic… and not just because I’m a freelance editor and prone to hours of reading. Words are powerful, conjuring images and ideas that can help those who read them change the world, or at least change their perception of the world. Perspective is a crucial part of our ability to survive and thrive. Words can build up and liberate or they can trap and enslave. They must be used wisely.

Quinion’s post got me thinking, Do I have my own grimoire for the craft of writing? As it turns out, I do. My grimoire, a notebook I keep while reading books on the craft of writing, is full of “spells, conjurations, instructions for [writing]… and other secret knowledge of a supernatural kind,” or helpful hints and encouraging quotes that I find as I go along through such books as Stephen King’s On Writing: 10th Anniversary Edition: A Memoir of the Craft or Betsy Lerner’s The Forest for the Trees (Revised and Updated): An Editor’s Advice to Writers. The words in my notebook are powerful, they’re the key to unlocking creative energy in myself and in my editing clients. They’re secrets and experience passed down by generations of practitioners of the craft of writing.

The cover of my Grimoire. “The Lightgatherers”
an original painting by Montserrat Bennett

We endow all sorts of people, objects and rituals with power over our writing, from our favorite authors to the reliability of our computers’ operating systems. Why not do something intentional and positive to add power to your writing? Start your own grimoire of your craft and fill it with powerful incantations from people who inspire you to be a weaver of words.