Chapter V: Part IV: Should We Try to Prolong Human Life?

I

THE BENEFIT TO HUMANITY

Complaints of the shortness of our life.—Theory of
“medical selection” as a cause of degeneration of the
race.—Utility of prolonging human life 132

II

SUGGESTIONS FOR THE PROLONGATION OF LIFE

Ancient methods of prolonging human life.—Gerokomy.—The
“immortality draught” of the Taoists.—Brown-Séquard’s
method.—The spermine of Poehl.—Dr. Weber’s
precepts.—Increased duration of life in historical
times.—Hygienic maxims.—Decrease in cutaneous cancer 136

III

DISEASES THAT SHORTEN LIFE

Measures against infectious diseases as aiding in the
prolongation of life.—Prevention of syphilis.—Attempts
to prepare serums which could strengthen the higher
elements of the organism 145

IV

INTESTINAL PUTREFACTION SHORTENS LIFE

Uselessness of the large intestine in man.—Case of
a woman whose large intestine was inactive for six
months.—Another case where the greater part of the
large intestine was completely shut off.—Attempts to
disinfect the contents of the large intestine.—Prolonged
mastication as a means of preventing intestinal
putrefaction 151

V

LACTIC ACID AS INHIBITING INTESTINAL PUTREFACTION

The development of the intestinal flora in
man.—Harmlessness of sterilised food.—Means
of preventing the putrefaction of food.—Lactic
fermentation and its anti-putrescent action.—Experiments
on man and mice.—Longevity in races which used
soured milk.—Comparative study of different soured
milks.—Properties of the Bulgarian Bacillus.—Means
of preventing intestinal putrefaction with the help of
microbes 161

PART V

PSYCHICAL RUDIMENTS IN MAN

I

RUDIMENTARY ORGANS IN MAN

Reply to critics who deny the simian origin of
man.—Actual existence of rudimentary organs.—Reductions
in the structure of the organs of sense in man.—Atrophy
of Jacobson’s organ and of the Harderian gland in the
human race 184

II

HUMAN TRAITS OF CHARACTER INHERITED FROM APES

The mental character of anthropoid apes.—Their muscular
strength.—Their expression of fear.—The awakening of
latent instincts of man under the influence of fear 191

III

SOMNAMBULISM AND HYSTERIA AS MENTAL RELICS

Fear as the primary cause of hysteria.—Natural
somnambulism.—Doubling of personality.—Some examples
of somnambulists.—Analogy between somnambulism and
the life of anthropoid apes.—The psychology of
crowds.—Importance of the investigation of hysteria for
the problem of the origin of man 200

PART VI

SOME POINTS IN THE HISTORY OF SOCIAL ANIMALS

I

THE INDIVIDUAL AND THE RACE

Problem of the species in the human race.—Loss
of individuality in the associations of lower
animals.—Myxomycetes and Siphonophora.—Individuality in
Ascidians.—Progress in the development of the individual
living in a society 212

II

INSECT SOCIETIES

Social life of insects.—Development and preservation of
individuality in colonies of insects.—Division of labour
and sacrifice of individuality in some insects 220

III

SOCIETY AND THE INDIVIDUAL IN THE HUMAN RACE

Human societies.—Differentiation in the human
race.—Learned women.—Habits of a bee, Halictus
quadricinctus.—Collectivist theories.—Criticisms by
Herbert Spencer and Nietzsche.—Progress of individuality
in the societies of higher beings 223

PART VII

PESSIMISM AND OPTIMISM

I

PREVALENCE OF PESSIMISM

Oriental origin of pessimism.—Pessimistic
poets.—Byron.—Leopardi.—Poushkin.—Lermontoff.—Pessimism
and suicide 233

II

ANALYSIS OF PESSIMISM

Attempts to assign reasons for the pessimistic conception
of life.—Views of E. von Hartmann.—Analysis of
Kowalevsky’s work on the psychology of pessimism 239

III

PESSIMISM IN ITS RELATION TO HEALTH AND AGE

Relation between pessimism and the state of the
health.—History of a man of science who was pessimistic
when young and who became an optimist in old
age.—Optimism of Schopenhauer when old.—Development of
the sense of life.—Development of the senses in blind
people.—The sense of obstacles 247