Discussion on the nature of intelligence long pre-dated the development of the
electronic computer, but along with that development came a renewed burst of investigation
into what an artificial intelligence would be. There is still no consensus on how
to define artificial intelligence: Early definitions tended to discuss the type of behaviours
which we would class as intelligent, such as a mathematical theorem proving or displaying
medical expertise of a high level. Certainly such tasks are signals to us that the
person exhibiting such behaviours is an expert and deemed to be engaging in intelligent
behaviours; however, 60 years of experience in programming computers has shown
that many behaviours to which we do not ascribe intelligence actually require a great
deal of skill. These behaviours tend to be ones which all normal adult humans find
relatively easy, such as speech, face recognition, and everyday motion in the world.
The fact that we have found it to be extremely difficult to tackle such mundane problems
suggests to many scientists that an artificial intelligence cannot simply display
the high-level behaviours of an expert but must, in some way, exhibit some of the lowlevel
behaviours common to human existence.
Yet this stance does not answer the question of what constitutes an artificial
intelligence but merely moves the question to what common low-level behaviours are
necessary for an artificial intelligence. It seems unsatisfactory to take the stance which
some do, that states that we would know one if we met one. This book takes a very
pragmatic approach to the problem by tackling individual problems and seeking to use
tools from the artificial intelligence community to solve these problems. The techniques
that are used tend to be those which are suggested by human life, such as
artificial neural networks and evolutionary algorithms. The underlying reasoning behind
such technologies is that we have not created intelligences through such highlevel
techniques as logic programming; therefore, there must be something in the actuality
of life itself which begets intelligence. For example, the study of artificial neural
networks is both an engineering study in that some practitioners wish to build machines
based on artificial neural networks which can solve specific problems, but it is
also a study which gives us some insight into how our own intelligences are generated.
Regardless of the reason given for this study, the common rationale is that there is
something in the bricks and mortar of brains — the actual neurons and synapses —
which is crucial to the display of intelligence. Therefore, to display intelligence, we are
required to create machines which also have artificial neurons and synapses.