by the golden circle. It was no matter to him what
light was like. So soon as it entered into his intention to represent
the appearance of light, he was not long in discovering the natural
facts necessary for his purpose.

Sec. XVIII. But, this being fully allowed, it is still true that the
accumulation of facts now known respecting visible phenomena, is greater
than any man could hope to gather for himself, and that it is well for
him to be made acquainted with them; provided always, that he receive
them only at their true value, and do not suffer himself to be misled by
them. I say, at their true value; that is, an exceedingly small one. All
the information which men can receive from the accumulated experience of
others, is of no use but to enable them more quickly and accurately to
see for themselves. It will in no wise take the place of this personal
sight. Nothing can be done well in art, except by vision. Scientific
principles and experiences are helps to the eye, as a microscope is; and
they are of exactly as much use _without_ the eye. No science of
perspective, or of anything else, will enable us to draw the simplest
natural line accurately, unless we see it and feel it. Science is soon
at her wits' end. All the professors of perspective in Europe, could
not, by perspective, draw the line of curve of a sea beach; nay, could
not outline one pool of the quiet water left among the sand. The eye and
hand can do it, nothing else. All the rules of aerial perspective that
ever were written, will not tell me how sharply the pines on the
hill-top are drawn at this moment on the sky. I shall know if I see
them, and love them; not till then. I may study the laws of atmospheric
gradation for fourscore years and ten, and I shall not be able to draw
so much as a brick-kiln through its own smoke, unless I look at it; and
that in an entirely humble and unscientific manner, ready to see all
that the smoke, my master, is ready to show me, and expecting to see
nothing more.

Sec. XIX. So that all the knowledge a man has must be held cheap, and
neither trusted nor respected, the moment he comes face to face with
Nature. If it help him, well; if not, but, on the contrary, thrust
itself upon him in an impertinent and contradictory temper, and venture
to set itself in the slightest degree in opposition to, or comparison
with, his sight, let it be disgraced forthwith. And the slave is less
likely to take too much upon herself, if she