doctor entered somewhat abruptly and did not seem to observe
Richard's presence. His eyes had a penetrating, almost fierce
expression and his brows were knit. He sat down to the table
mechanically, and ate what was placed before him. It is questionable
whether he knew what he was eating, or even that he was eating. He did
not speak a word, and Frank, who knew his peculiarities, did not
disturb him by a single syllable. This was not difficult, as he was
busily occupied with his own thoughts.

After the meal was over, Klingenberg came to himself. "My dear Richard,
I beg your pardon," said he in a tone of voice which was almost tender.
"Excuse my weakness. I have read this morning a scientific article that
upsets all my previous theories on the subject treated of. In the whole
field of human investigation there is nothing whatever certain, nothing
firmly established. What one to-day proves by strict logic to be true,
to-morrow another by still stronger logic proves to be false. From the
time of Aristotle to the present, philosophers have disagreed, and the
infallible philosopher will certainly never be born. It is the same in
all branches. I would not be the least astonished if Galileo's system
would be proved to be false. If the instruments, the means of acquiring
astronomical knowledge, continue to improve, we may live to learn that
the earth stands still and that the sun goes waltzing around our little
planet. This uncertainty is very discouraging to the human mind. We
might say with Faust,

"'It will my heart consume
That we can nothing know.'"

"In my humble opinion," said Frank, "every investigator moves in a
limited circle. The most profound thinker does not go beyond these set
limits; and if he would boldly overstep them, he would be thrown back
by evident contradiction into that circle which Omnipotence has drawn
around the human intellect."

"Very reasonable, Richard; very reasonable. But the desire of knowledge
must sometimes be satiated," continued the doctor after a short pause.
"If the human mind were free from the narrow limits of the deceptive
world of sense, and could see and know with pure spiritual eyes, the
barriers of which you speak would fall. Even the Bible assures us of
this. St. Paul, writing to the Corinthians, says, 'We see now through a
glass in an obscure manner, but then face to face; now I know in part,
but then I shall know as I am known.' I would admi