Here is an earlier version of my post for CultureLab at New Scientist:
Bestiaries – compendia of stories about real and imaginary animals – are among the great artistic achievements of the European High Middle Ages, as notable for their gorgeously illuminated images as they are for their strange conjoining of fantastical supposition with religious and moral instruction.
The panther, for example, is a brightly-coloured beast from whose mouth comes a sweet odour, as if it were a mixture of every perfume. “Other animals, hearing its voice, follow wherever it goes because of the sweetness of its scent. Only the dragon is seized by fear and flees into the caves beneath the earth.” In the accompanying illustration, gold leaf depicting the air around the panther's mouth is ribbed and waved in such a way that it appears to move as you turn the page. “Thus,” continues the text, “our Lord Jesus Christ, the true panther, descended from heaven and saved us from the power of the devil.”
Other depictions are less elevated. The Bonnacon, which resembles a bull, has curved-in horns that are no good for fighting so it saves itself from its enemies by projectile-evacuating a long stream of acrid excrement. Scores of other animals, many of them chimerical combinations of real ones, fill these pages.
Through the Renaissance, the scientific revolution and into the modern age, myth and legend have given way to new discoveries in the real world. The realm of wonder has expanded to include ever more real creatures that were previously unimagined by Europeans and that often no less extraordinary than those depicted in a medieval bestiary. Think what it must have been like to have seen a platypus – an egg-laying mammal with a snout like a duck – for the first time. Over the centuries, cabinets of curiosities, zoos and botanical gardens and wildlife television documentaries have helped to meet our insatiable appetite for novelty and our desire to have better sense of what, beyond our own pressing daily concerns, the world contains. You need only open the pages of a magazine such as New Scientist in any given week to learn of some astonishing discovery that casts light on one or several of the endless forms most beautiful – and passing strange – that have been, and are being evolved.
Life – a work in progress, a constant experiment – has its own Ig Nobels: creatures which no sane creator could have imagined, and which make you laugh, or gasp in astonishment, and then make you think. Consider the leafy seadragon, which looks more like seaweed than seaweed does and is at the same time unutterably weird, or the sea slug Elysia chlorotica which photosynthesises with genes stolen from the algae it eats and is as green as a leaf. Marvel at the barreleye fish, whose eyes facing upwards underneath a transparent dome like the seats in the cockpit of a helicopter, or the Giant tubeworms that thrive in scorching black sulphurous smoke on the seabed and which are taller than men but have no digestive tract. Dive into deep time and picture the pterosaurs – featherless flying reptiles that in some species grew as big as giraffes and had crests on their heads at least as big and probably as colourful as anything at the Rio carnival.
Bestiaries are full of allegory and symbol because, for the medieval mind, everything was believed to embody a religious or moral lesson. Thinkers and scientists such as Hume and Darwin discredited this way of looking at nature. In at least two respects, however, the world is becoming allegorical again.
Firstly, as humans increasingly twist the world to serve our purposes and our growing numbers we leave ever less space for other animals to evolve independently. Secondly, our ingenuity is making it possible to entirely new organisms “from an idea rather than an ancestor” as an editorial in Nature on the 150th anniversary of the publication of Darwin's Origin of Species put it.
Medieval bestiaries give a striking, delightful and sometimes hilarious picture of a thirteenth century world-view. In some respects, however, our own times are not so very different. We are still animals that dream and for the most part seek meaning. We need to dream uninhibitedly but act responsibly and with humility.