Bartholomew brings the idea of mission vividly before the reader through two reiterated sets of images, each of which carries an accessible moral subtext. One of these involves realistic and dramatic descriptions of the ocean; the other evokes well-known stories about archetypal travellers over land and sea.
In long chapters on the sea and on fishes in Book 13, Bartholomew compiles empirical-seeming descriptions of the ocean as a heaving mass of water, speculations on the nature of saltiness, descriptions of lunar influence and tides, the sea bed and sea monsters, and the great variety of the underwater world of fishes. In De mari, Bartholomew paints a vivid picture of the open sea, with its dangers to sailors: waves, weather, monsters, sandbanks, sea-sickness, distance from land. He cites Aristotle and others on the medicinal properties of sea water, its incessant motion and changeable colours under different winds. Both fog and wind are perilous to those coming towards shore and a ship may be imperilled or late coming to harbour if it is weak, overloaded or poorly steered.[14] He goes on to depict some formidable dangers to shipping: the rock Scylla and the whirlpool Charybdis that nearly destroyed Odysseus; hidden rocks, sandbanks, and an indeterminate hazard where the bow gets stuck and the stern breaks, called bitalapsum; and uneven deeps and shallows called sirtes.[15] These were real hazards which any prospective traveller needed to be aware of, and Bartholomew devotes a separate chapter to the Sirtes in Book 15, treating them as a named location off the coast of Egypt and citing their etymological meaning of drawing or dragging.[16]
Some of these dangers, then, were and are real enough. Bartholomew states: ‘These are dangers for men who sail on the sea, both the Mediterranean and Ocean’, but in the midst of describing them he pauses to say that, while many common things are known about the sea, he wants to make sure that his readers have matter with which to persuade simple men of spiritual and hidden truths.[17] In other words, he’s talking about the moral as well as physical dangers that the traveller might encounter. The glossator's copious comments confirm that readers could draw deeper connotations of the commotion and dangers of worldly life from under the surface description. They warn that sirtes point us to the lure of worldly wealth that can wreck one’s hopes of salvation: ‘Take note of the condition of the worldly; of the rise and fall of the worldly man; of love of the world and its danger; be on your guard against riches.’ At the start of the chapter on the sea, where Bartholomew describes the continual movement, waves and storms, the glossator has written: ‘Take note of the condition of the worldly.’[18] Comments against the ensuing column text on rocks and wild weather include: ‘Take note concerning usurers and rich men … concerning the pride and self-importance of the wealthy … of the infirmity of the body and soul … of mortal sin.’ Against the monsters Scylla and Charybdis, the glossator warns of the changeableness of the world, and its strong appeal: ‘Take care against prosperity and adversity in the world; against love of the world and its danger.’ Where Bartholomew cites Aristotle on the way the sea becomes changeable in colour in the ‘dog days’ after the rising of the dog-star canicula, the glosses include: ‘Take note of Antichrist.’[19] Bartholomew’s chapter on the open ocean, pelagus, describes a dangerous shoreless waste, very deep and constantly in motion, home of whales and other monsters, windy and full of spray, changing colours, and the din of crashing waves; the glossator likens these to ‘worldly tumult’ and ‘the mutability of worldly things’.[20] A warning against the fatal attraction or ‘drawing’ implied in the etymology of sirtes appears again in Book 18 in Bartholomew's chapter on the siren, the monster that seeks to destroy mariners by luring them off course with song, holding out false promises and arousing their lust.[21] The glossator sees them as reminders of love of the world; the desire of the flesh, lust of the eyes and pride of life; and as warnings against envy, pride and hypocrisy.[22] Within the sea lurk creatures of all kinds, just as people of all kinds inhabit the world.[23] These glosses demonstrate a reader’s contemplative response to a dynamic description of physical experience. They also show us a stage in the process by which the sea — unstable, stormy and full of monstrous danger — became such a fruitful metaphor in the later Middle Ages for the world of secular society.
We have seen that Bartholomew’s own justification for his work, that the things that are made show us the invisible things of God, recalls Augustine’s teaching. He repeats this statement in Book 8 on the sublunary world.[24] Similarly, he seems to refer to St Augustine’s mention of a necessary mode of conveyance near the start of his own literary undertaking. As stated earlier, he explains in Book 3 that the soul is said to be one with the body — but guides it, as a sailor is one with a ship — a non-bodily substance ruling the body.[25] For the Franciscan student such a reading could be appropriate as an Augustinian vision of spiritual pilgrimage; but Bartholomew also provides reminders of the need for courage and faith. In Book 8, the North Star, stella maris, reassures those who look on its fixedness, and guides the mariner.[26] In Book 13, Bartholomew describes the little fish aphorus as very small but full of virtue because it clings to a ship and holds it still and steady in the midst of storms, as Isidore says. Ambrose and Bede say that these fish use stones to help them stabilise ships with a strength beyond their own; they warn sailors to be ready for the coming tempest.[27] In Book 15, the island resists the onslaught of waves.[28] In Book 17, a plank of wood can save the shipwrecked sailor.[29] Like the glossator, Bartholomew seems to encourage the reader to identify with the sinner aware of being perilously exposed on the open ocean of worldly life.