it be at hand, the ear sound. Three of these senses are of
commodity, hearing, sight, and smell; two of necessity, touch, and taste,
without which we cannot live. Besides, the sensitive power is active or
passive. Active in sight, the eye sees the colour; passive when it is hurt
by his object, as the eye by the sunbeams. According to that axiom,
_visibile forte destruit sensum_. [982]Or if the object be not pleasing, as
a bad sound to the ear, a stinking smell to the nose, &c.

_Sight_.] Of these five senses, sight is held to be most precious, and the
best, and that by reason of his object, it sees the whole body at once. By
it we learn, and discern all things, a sense most excellent for use: to the
sight three things are required; the object, the organ, and the medium. The
object in general is visible, or that which is to be seen, as colours, and
all shining bodies. The medium is the illumination of the air, which comes
from [983]light, commonly called diaphanum; for in dark we cannot see. The
organ is the eye, and chiefly the apple of it, which by those optic nerves,
concurring both in one, conveys the sight to the common sense. Between the
organ and object a true distance is required, that it be not too near, or
too far off! Many excellent questions appertain to this sense, discussed by
philosophers: as whether this sight be caused _intra mittendo, vel extra
mittendo_, &c., by receiving in the visible species, or sending of them
out, which [984]Plato, [985]Plutarch, [986]Macrobius, [987]Lactantius and
others dispute. And, besides, it is the subject of the perspectives, of
which Alhazen the Arabian, Vitellio, Roger Bacon, Baptista Porta, Guidus
Ubaldus, Aquilonius, &c., have written whole volumes.

_Hearing_.] Hearing, a most excellent outward sense, "by which we learn and
get knowledge." His object is sound, or that which is heard; the medium,
air; organ, the ear. To the sound, which is a collision of the air, three
things are required; a body to strike, as the hand of a musician; the body
struck, which must be solid and able to resist; as a bell, lute-string, not
wool, or sponge; the medium, the air; which is inward, or outward; the
outward being struck or collided by a solid body, still strikes the next
air, until it come to that inward natural air, which as an exquisite organ
is contained in a little skin formed like a drum-head, and struck upon by
certain small instruments like drum-sticks, conveys the sound by a p