nd a pipe of tobacco. On this he worked eight hours, either in
lecturing or writing--a long stretch of uninterrupted labor. He dined at
one, and this was his only meal, for he had no supper. The single repast
was a deviation from ordinary usage, but Kant found that it suited him,
probably because he read in the evening from six till a quarter to ten,
and a second meal might have interfered with this by diminishing his
power of attention. There exists a strong medical objection to this
habit of taking only one meal in twenty-four hours, which indeed is
almost unknown in England, though not extremely rare on the Continent. I
know an old gentleman who for forty years has lived as Kant did, and
enjoys excellent health and uncommon mental clearness.

A detail which illustrates Kant's attention to whatever could affect his
physical life, is his rule to withdraw his mind from everything
requiring effort fifteen minutes before he went to bed. His theory,
which is fully confirmed by the experience of others, was, that there
was a risk of missing sleep if the brain was not tranquillized before
bed-time. He knew that the intellectual life of the day depended on the
night's rest, and he took this precaution to secure it. The regularity
of his daily walk, taken during the afternoon in all weathers, and the
strict limitation of the hours of rest, also helped the soundness of his
sleep.

He would not walk out in company, for the whimsical reason that if he
opened his mouth a colder air would reach his lungs than that which
passed through the nostrils; and he would not eat alone, but always had
guests to dinner. There are good physiological reasons in favor of
pleasant society at table, and, besides these, there are good
intellectual reasons also.

By attention to these rules of his, Kant managed to keep both body and
mind in a working order, more uninterrupted than is usual with men who
go through much intellectual labor. The solitary objection to his system
is the excessive regularity of habit to which it bound him by chains of
his own forging. He found a quiet happiness in this regularity; indeed,
happiness is said to be more commonly found in habit that in anything
else, so deeply does it satisfy a great permanent instinct of our
nature. But a _minute_ regularity of habit is objectionable, because it
can only be practicable at home, and is compatible only with an
existence of the most absolute tranquillity. Kant did not travel, a