1920s:

Scientist Ivan Pavlov conducts behavioral experiments and shows that one can create a conditioned response in animals. John B. Watson, establishes the Behaviorist School of thought: he believes that human beings can be reduced to a network of stimuli and responses, which can be controlled by the experimenter.

1930s: German Nobel Prize winner Hans Spemann develops the controversial science of experimental embryology, manipulating the experience of a human fetus in the womb in order to influence it.

Huxley's London 731 A.D.: All humans are cloned from a small number of fertilized eggs, incubated in artificial wombs (bottles), and conditioned as embryos and fetuses for their future lives.

Today: In 1978, the first human baby conceived in vitro (in a test tube) is born. In 1997, a sheep is cloned for the first time, raising the possibility of cloning humans.

1920s: Totalitarian rulers Joseph Stalin in...