Conversation so far:
What did Wilhelm Stekel think about neurosis?
Stekel made significant contributions to symbolism in dreams, as successive editions of The Interpretation of Dreams attest, with their explicit acknowledgement of Freud's debt to Stekel.
How did Wilhelm Stekel make these significant contributions to symbolism in dreams?
Stekel wrote one of a set of three early Psychoanalytic studies of psychical impotence referred to approvingly by Freud: Freud had written a preface to Stekel's book.

Question: What is psychical impotence?
Self-contained rewrite: What is Wilhelm Stekel's theory of psychical impotence?