Psychiatric practices are changing. New social demands emerge. It is i
n this context that the author questions the institutional dimension o
f the therapeutic foster care, through the notion of training applied
to the foster families. He puts forward a theory of the ''containment'
' of the set constituted by the foster families and the rest of the in
stitution, referring himself in particular to the works of Bion. He pl
eads for more ethical rigour in a still little known field, and for th
e recognition of the status professional foster families based on spon
taneous capacities which he calls ''primordial caring preoccupation''.