SECONDLY, it seems impossible
by this hypothesis to account for the moon's appearing in the very same
situation at one time greater than at another; which nevertheless has
been shown to be very agreeable to the principles we have laid down, and
receives a most easy and natural explication from them. For the further
clearing' up of this point it is to be observed that what we immediately
and properly see are only lights and colours in sundry situations and
shades and degrees of faintness and clearness, confusion and
distinctness. All which visible objects are only in the mind, nor do they
suggest ought external, whether distance or magnitude, otherwise than by
habitual connexion as words do things. We are also to remark that, beside
the straining of the eyes, and beside the vivid and faint, the distinct
and confused appearances (which, bearing some proportion to lines and
angles, have been substituted instead of them in the foregoing part of
this treatise), there are other means which suggest both distance and
magnitude; particularly the situation of visible points of objects, as
upper or lower; the one suggesting a farther distance and greater
magnitude, the other a nearer distance and lesser magnitude: all which is
an effect only of custom and experience; there being really nothing
intermediate in the line of distance between the uppermost and lowermost,
which are both equidistant, or rather at no distance from the eye, as
there is also nothing in upper or lower, which by necessary connexion
should suggest greater or lesser magnitude.
Pages:
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68