Van Gelder's clear distinction between the quantitative
nature of dynamical systems and the nonquantitative nature of
computational processes provides a firm basis for distinguishing
between processes that happen in time and processes that
happen over time. Symbolic reasoning, the presumed basis of
intelligent behavior in robots, happens over time. However,
the movements and actions that robots must make to behave
intelligently, happen in time. Attempting to connect the two,
as classical artificial intelligence and robotics have presumed to be
necessary, has produced a tension and an arbitrarily moving interface
in the construction of robots. Adopting a robotic version of the
dynamical hypothesis offers sound theoretical and scientific
justification for those robotics researchers who continue to insist
that getting the interaction dynamics of intelligent behavior right
is a purely dynamical matter, and never a symbolic computational
one.