ts of animals. A number of marine animals ... go away
from the light, can be forced to go to light in two ways, first by
lowering the temperature and second by increasing the
concentration of the sea water, whereby the cells of the animals
lose water. This instinct can be again reversed by raising the
temperature or by lowering the concentration of the sea water. I
have found repeatedly that by the same conditions by which
phenomena of growth and organization can be controlled the
instincts are controlled also. This indicates that there is a
common basis for both classes of life phenomena. This common base
is the physical and chemical character of the mixture of
substances which we call protoplasm.... _The greatest happiness in
life_ can be obtained only if _all instincts_, that of workmanship
included, can be maintained at a certain _optimal intensity_. But
while it is certain that the individual can ruin or diminish the
value of its life by a onesided development of its instincts,
e.g., dissipation, it is at the same time true that the _economic
and social conditions can ruin or diminish the value of life for a
great number of individuals_. It is no doubt true that in our
present social and economic conditions more than ninety per cent
of human beings lead an existence whose value is far below what it
should be. They are compelled by want to sacrifice a number of
instincts especially the most valuable among them, that of
workmanship, in order to save the lowest and most imperative, that
of eating. If those who amass immense fortunes could possibly
intensify their lives with their abundance, it might perhaps be
rational to let many suffer in order to have a few cases of true
happiness. But for an increase of happiness only that amount of
money is of service which can be used for the harmonious
development and satisfaction of inherited instincts. For this,
comparatively little is necessary. The rest is of no more use to a
man than the surplus of oxygen in the atmosphere. As a matter of
fact, the only true satisfaction a multimillionaire can possibly
get from increasing his fortunes, is the satisfaction of the
instinct of workmanship or the pleasure that is connected with a
successful display of energy. The scientist gets this satisfaction
without diminishing the value of life of