Mind, Body, World- Foundations of Cognitive Science, 2013a

intractable. For instance, Ashby (1956) realized that feedback amongst a machine
that only consisted of four simple components could not analyzed:
When there are only two parts joined so that each affects the other, the properties
of the feedback give important and useful information about the properties of the
whole. But when the parts rise to even as few as four, if everyone affects the other
three, then twenty circuits can be traced through them; and knowing the properties
of all the twenty circuits does not give complete information about the system.
(Ashby, 1956, p. 54)
For this reason, embodied cognitive science is often practised using forward engineering,
which is a kind of synthetic methodology (Braitenberg, 1984; Dawson, 2004;
Pfeifer & Scheier, 1999). That is, researchers do not take a complete agent and
reverse engineer it into its components. Instead, they take a small number of simple
components, compose them into an intact system, set the components in motion in
an environment of interest, and observe the resulting behaviours.
For instance, Ashby (1960) investigated the complexities of his four-component
machine not by dealing with intractable mathematics, but by building and
observing a working device, the Homeostat. It comprised four identical machines
(electrical input-output devices), incorporated mutual feedback, and permitted
him to observe the behaviour, which was the movement of indicators for each
machine. Ashby discovered that the Homeostat could learn; he reinforced its
responses by physically manipulating the dial of one component to “punish” an
incorrect response (e.g., for moving one of its needles in the incorrect direction).
Ashby also found that the Homeostat could adapt to two different environments
that were alternated from trial to trial. This knowledge was unattainable from
mathematical analyses. “A better demonstration can be given by a machine, built
so that we know its nature exactly and on which we can observe what will happen
in various conditions” (p. 99).
Braitenberg (1984) has argued that an advantage of forward engineering is that
it will produce theories that are simpler than those that will be attained by reverse
engineering. This is because when complex or surprising behaviours emerge, preexisting
knowledge of the components—which were constructed by the researcher—
can be used to generate simpler explanations of the behaviour.
Analysis is more difficult than invention in the sense in which, generally, induction
takes more time to perform than deduction: in induction one has to
search for the way, whereas in deduction one follows a straightforward path.
(Braitenberg, 1984, p. 20)
Braitenberg called this the law of uphill analysis and downhill synthesis.
Another way in which to consider the law of uphill analysis and downhill synthesis
is to apply Simon’s (1969) parable of the ant. If the environment is taken
218 Chapter 5