Walden | Page 7

establish their lives on that basis.
Let us consider for a moment what most of the trouble and anxiety which I have referred
to is about, and how much it is necessary that we be troubled, or at least careful. It would
be some advantage to live a primitive and frontier life, though in the midst of an outward
civilization, if only to learn what are the gross necessaries of life and what methods have
been taken to obtain them; or even to look over the old day-books of the merchants, to
see what it was that men most commonly bought at the stores, what they stored, that is,
what are the grossest groceries. For the improvements of ages have had but little
influence on the essential laws of man's existence; as our skeletons, probably, are not to
be distinguished from those of our ancestors.
By the words, necessary of life, I mean whatever, of all that man obtains by his own
exertions, has been from the first, or from long use has become, so important to human
life that few, if any, whether from savageness, or poverty, or philosophy, ever attempt to
do without it. To many creatures there is in this sense but one necessary of life, Food. To
the bison of the prairie it is a few inches of palatable grass, with water to drink; unless he
seeks the Shelter of the forest or the mountain's shadow. None of the brute creation
requires more than Food and Shelter. The necessaries of life for man in this climate may,
accurately enough, be distributed under the several heads of Food, Shelter, Clothing, and
Fuel; for not till we have secured these are we prepared to entertain the true problems of
life with freedom and a prospect of success. Man has invented, not only houses, but
clothes and cooked food; and possibly from the accidental discovery of the warmth of fire,
and the consequent use of it, at first a luxury, arose the present necessity to sit by it. We
observe cats and dogs acquiring the same second nature. By proper Shelter and Clothing
we legitimately retain our own internal heat; but with an excess of these, or of Fuel, that
is, with an external heat greater than our own internal, may not cookery properly be said

to begin? Darwin, the naturalist, says of the inhabitants of Tierra del Fuego, that while his
own party, who were well clothed and sitting close to a fire, were far from too warm,
these naked savages, who were farther off, were observed, to his great surprise, "to be
streaming with perspiration at undergoing such a roasting." So, we are told, the New
Hollander goes naked with impunity, while the European shivers in his clothes. Is it
impossible to combine the hardiness of these savages with the intellectualness of the
civilized man? According to Liebig, man's body is a stove, and food the fuel which keeps
up the internal combustion in the lungs. In cold weather we eat more, in warm less. The
animal heat is the result of a slow combustion, and disease and death take place when this
is too rapid; or for want of fuel, or from some defect in the draught, the fire goes out. Of
course the vital heat is not to be confounded with fire; but so much for analogy. It appears,
therefore, from the above list, that the expression, animal life, is nearly synonymous with
the expression, animal heat; for while Food may be regarded as the Fuel which keeps up
the fire within us -- and Fuel serves only to prepare that Food or to increase the warmth
of our bodies by addition from without -- Shelter and Clothing also serve only to retain
the heat thus generated and absorbed.
The grand necessity, then, for our bodies, is to keep warm, to keep the vital heat in us.
What pains we accordingly take, not only with our Food, and Clothing, and Shelter, but
with our beds, which are our night-clothes, robbing the nests and breasts of birds to
prepare this shelter within a shelter, as the mole has its bed of grass and leaves at the end
of its burrow! The poor man is wont to complain that this is a cold world; and to cold, no
less physical than social, we refer directly a great part of our ails. The summer, in some
climates, makes possible to man a sort of Elysian life. Fuel, except to cook his Food, is
then unnecessary; the sun is his fire, and many of the fruits are sufficiently cooked by its
rays; while Food generally is more various, and more easily obtained, and Clothing and
Shelter are wholly or half unnecessary. At the present day, and in this country, as