This post is part of a blog series on historical data vis titled “Data Trails. Snapshots from the history of data visualisation” and originally appeared over at my friends’ from Idalab, a Berlin-based specialist on data science and machine learning.
Do you know that thing when you draft a project and anticipate it will come out nicely, and once you actually start looking into it, things get really complicated? This is what happened to me with this severe beauty of a tree diagram here. I stumbled upon it in the Beinecke digital collections and was immediately thrilled about this hidden gem from back in 1608. Then I never came around to really studying it — until just now.
Now, Christian theology is not exactly a field of knowledge I am well schooled in. The cleric William Perkins, the author of the diagram, lived from 1558 to 1602, so we’re talking Shakespearean times here. It was an age of religious debate, as the Anglican church tried to define its spiritual position between Roman catholics and reformed confessions from the continent (such as Lutheran or Calvinist). Perkins himself taught and preached in Cambridge. Many students praised him as a charismatic religious leader, who excelled in bringing about spiritual experiences in his audiences.
He achieved a long-term influence when his works were posthumously published and translated to several European languages. It is in these books that the wonderful tree diagram has been handed down to us. So what is it all about? Let’s look: „The red line [uncoloured, i.e. the thick white line in our copy] shows the order of the causes of salvation from the first to the last. The black line shows the order of the causes of damnation.“
Ok, salvation and damnation. Puritan movement in early modern England. Some creative Google searches turned up the Christian doctrine of predestination as the apparent base for this piece. It holds that everything happening on Earth was willed and foreseen by God, who predetermined the fate of every individual even before (!) Creation. The doctrine had been discussed since the early days of Christianity and was an important concept to the puritans. Our tree spells out the core ideas of this doctrine as a memorizing tool for believers.
Here is the source of power, the root from which God’s grace and wrath trickles down onto the believing individual: the Holy Trinity, represented through the Father, the Son and the Holy Ghost. Look at how they communicate: Strange „cursors“ point from Father to Son, and from both to the Holy Ghost. And from this point downwards, the world is divided into the Good and the Bad. First after the Holy Trinity comes God’s foreknowledge, second his decree which parts the blessed souls from the damned ones. Only then, God sets out to create the world, to create life, to create man.
Now here we’re deep in the mist, we see complexity spread out in nodes and connecting graphs. I will not pretend I fully understand the fine-grained nuances of righteous Christian behaviour as spelled out on the left, and sinful behaviour as spelled out on the right. However, it is appealing how the author managed to carve out a number of discreet ideas and arranged them in a vertical symmetry which indicates a succession of steps—from God’s decree at the top to life in Heaven or Hell at the bottom.
It’s great how this diagram displays its protestant mindset in its design—it is strictly black and white, with no ornate decoration, layed out in a strong symmetry. Its look invokes the intellectual rigour that Perkins and his peers claimed for themselves.
What I like is the diagram’s educational intention. It is common sense today that visuals help in learning of difficult theories. Back at the time, this idea was not anything as prevalent as it is now. At the same time, protestant movements demanded that normal people with just a rudimentary education actually understood their teachings.
Perkins had conceived his diagram as a supporting tool for lay people, including illiterates, who could memorize the elements by pointing at them with their finger. Whether this actually worked we may never be able to judge. But I like to think about it as a sort of exosceleton. It creates a solid visual structure for something which would otherwise remain an unmanageable mass of words and text.
Images via the Yale University Beinecke Rare Book & Manuscript Library. A beautiful collection of tree diagrams (old and new) can be found in Manuel Lima’s „Book of Trees“.