In
the 19th and early 20th centuries, there was a school of psychology
known as structuralism, represented by such figures as Wilhelm Wundt
and Edward B. Titchener. The structuralists used introspection to
attempt to describe the elementary components of the human mind. For
example, according to the structuralists, a sensory perception was
based on the structure of the associations between numerous sensations
(whence the name “structuralism”). The structuralists believed that by
describing the possible
combinations of these elements, they could deduce laws as general and
powerful as those governing the physical world. The structuralist
approach was criticized not only because of its implicit dualism, but
also because of the difficulty of experimentally testing the
introspection on which it was based. In response, another school of
thought emerged that was radically
opposed to structuralism. This school was known as behaviourism.
According to its pioneers, such as John B. Watson and B. F. Skinner, no
scientific approach to psychology could be built on subjective states,
which are essentially private. In contrast, their new psychology would
be based not on personal judgments about feelings and states of mind,
but solely on the experimental study of behaviour. To make psychology a
true science, the behaviourists decided to study
only observable phenomena: the stimuli to which an organism is
subjected, and the responses that it makes to these stimuli. The
behaviourists thus treated the brain as a “black box”, in the sense
that they regarded what happened inside it as being unobservable by its
very nature