  It is argued that, for strongly non-linear behaviors, a fully deterministic
position can hardly be maintained in the micro-macro transitions. This is due
to the lack of information on the relevant boundary conditions, and to the
tendency of non-linear dynamical systems to have a "horizon of predictibility".
In the variational micro-macro model proposed by us, the data of the
microscopic behavior plus the overall stimulus has to be supplemented by a
"heterogeneity parameter". In this model, the macro-to-micro transition depends
on the validity of a "principle of minimal heterogeneity" (PMH). It is shown
that the PMH has a close relation to the maximum entropy principle.
