  Following a recent suggestion that the $\Theta ^+$ could be a $K \pi N$ bound
state we perform an investigation under the light of the meson meson and meson
baryon dynamics provided by the chiral Lagrangians and using methods currently
employed to dynamically generate meson and baryon resonances by means of
unitary extensions of chiral perturbation theory. We consider two body and
three body forces and examine the possibility of a bound state below the three
particle pion-kaon-nucleon and above the kaon-nucleon thresholds. Although we
find indeed an attractive interaction in the case of isospin I=0 and
spin-parity $1/2^+$, the interaction is too weak to bind the system. If we
arbitrarily add to the physically motivated potential the needed strength to
bind the system and with such strong attraction evaluate the decay width into
$K N$, this turns out to be small. A discussion on further work in this
direction is done.
