Definition
Psychology knows psychophysical parallelism - the interplay of body and psyche (e.g. psychosomatic illnesses). Frankl added noo-psychic antagonism: the spiritual dimension (nous) can stand up to what is psychological - fear, mood, impulse.
This is the “resistance of the spirit”, also called the defiant power of the spirit (Trotzmacht des Geistes).
Significance for therapy
If there were no such antagonism, psychotherapy would be impossible - including in anxiety disorders, depression or even psychoses. The techniques of paradoxical intention and dereflection operate in this space.
Example
A man in deep grief, passed “from hand to hand” by family and friends, at some point says: “Everyone has their own place - I'm going back home.” This is the moment when the resistance of the spirit speaks and change begins.
Sources
V. E. Frankl, Homo patiens; The Doctor and the Soul; Viktor Frankl Institut Wien - biography.