The Goal of the Wise

A medieval illuminated manuscript page featuring various marginal illustrations.

• Top left margin: A simple outline drawing of a white bird, likely a goose or duck.
• Middle left margin: A detailed miniature of a figure (possibly Frederick II) seated on a decorated red and gold folding chair (faldstool). He wears a green tunic, a red mantle, and a white coif, holding a dark bird of prey on his gloved right hand.
• Right margin: A vertical column of four bird illustrations including a goose, a duck, a swan, and a long-legged wading bird (a crane or heron) at the bottom near blue-flowered plants.
• Bottom right: A miniature depicting two men in a wooden rowing boat on green-blue water. One man is actively rowing with a long oar.
• A large watermark/stamp from the "Biblioteca Apostolica Vaticana" is superimposed across the center of the image.

And what Aristotle senses in the book [of] Animals, saying that those birds are of modest flight whose whole [effort] is in [their] gait. For the flight of the diver is modest [and] their gait is from the few. But if this is understood as not universal and general, it is true. Concerning aquatic [birds], however, the modest flight is not so [for all]. Aquatic swimming birds, for the reason that it is expedient for them to remain in the waters, have been given by nature their feet distorted for swimming, more than for walking, and almost all [those that are] swimming, whether they are of those that fly well or of those that fly poorly, are of poor gait. The reason, however, why swimming birds are of poor gait is this: because when such birds are suitably born for swimming on account of the nourishment that they acquire for themselves by swimming in this way, [nature] has given them short shins original: "tibias" so that they might propel themselves better, more strongly, and more easily by swimming through the waters. For if they had long shins, it would be too difficult for them to propel themselves by swimming, since it would be necessary for them to have their shins, because of their length, be immersed too deeply [and] touch and enter the waters. And when the waters are deep, as they are farther removed from the stable air, [they] are not felt, [so they are] not making as much resistance. When one thing, namely,

the [water] being brought [to bear], leads [the bird], and furthermore it happens on account of the mixing of air, that the water itself ambiguously sustains the swimming body. And when it is necessary that two things be led by swimming through the surface, namely the water itself and the air which is joined to it, they oppose [the bird] and make greater resistance on account of the swimming [bird] in the water, by leading and extending the body toward the rear, and thus they propel [themselves] more [effectively]. If the birds themselves had long shins, by leading them through the depth of the waters, they could not make such an impulse, since such resistance is not found in the deep as that which a bird makes with its short shins, which are led through the surface of the water, which helps the impulse more. We have an example of this in galleys; see that if rowers wish to navigate more strongly with oars, they do not put the oars very deeply through the water, but they hold them high, leading them near the surface of the water. To this end, so that the water itself, by resisting more strongly against the oars near the surface, the galley might be propelled better and run more quickly. It would also happen because of this [that], after the bird in swimming extended its long shins in such a way, it could scarcely draw them back to itself: which it would do subsequently and more often...