diff --git a/books/psicologia/psychology-of-intelligence.mdwn b/books/psicologia/psychology-of-intelligence.mdwn
index b4a3538d590b73bb4694dbf4d8c3822dcf288817..a725a4cab0e455360c907aefe509fc40d2fce730 100644
--- a/books/psicologia/psychology-of-intelligence.mdwn
+++ b/books/psicologia/psychology-of-intelligence.mdwn
@@ -45,3 +45,28 @@
     (and, no doubt, vice versa).
 
     -- page 30
+
+    It is true that in addition to the individual consistency of
+    actions there enter into thought interactions of a collective order
+    and consequently “norms” imposed by this collaboration. But
+    co-operation is only a system of actions, or of operations, car-
+    ried out in concert, and we may repeat the preceding argument
+    for collective symbolic behaviour, which likewise remains at a
+    level containing real structures, unlike axiomatizations of a
+    formal nature.
+
+    For psychology, therefore, there remains unaltered the prob-
+    lem of understanding the mechanism with which intelligence
+    comes to construct coherent structures capable of operational
+    combination; and it is no use invoking “principles” which this
+    intelligence is supposed to apply spontaneously, since logical
+    principles concern the theoretical pattern formulated after
+    thought has been constructed and not this living process of con-
+    struction itself. Brunschvicg has made the profound observation
+    that intelligence wins battles or indulges, like poetry, in a con-
+    tinuous work of creation, while logico-mathematical deduction
+    is comparable only to treatises on strategy and to manuals of
+    “poetic art”, which codify the past victories of action or mind
+    but do not ensure their future conquests. 1
+
+    -- page 34