In silence between therapist and client we see how transactions (non silence) can drag the client’s psychological energy from the unconscious into the conscious
This diagram shows of how Freud conceived of the conscious and unconscious. In the human psyche there is a little bit of conscious at the top but most of it is the preconscious or unconscious underneath.
When a therapist talks to the client the person’s energy or attention is being taken away from the unconscious and is being forced into the conscious at the top. With silence this distraction stops and the person has the opportunity to be influenced by their unconscious urges and needs. This may happen or it may not, the therapist has to wait and see what the client produces at the end of the silence.
As someone recently said “this is the moment when new meanings are born, when you can hear yourself”.
This allows the client to reset the focus of therapy. The client is telling the therapist what is important for them right at this point of time in the therapy. However the therapist needs to make a judgement as to the “goodness or badness” of this change of topic by the client.
Alas, practice is rarely as easy as theory. You mention “goodness or badness” (not sure I like the word bad?) but even before that point there must be blockages / defences to keep the deep unconscious at bay?
I like the comment “…when you can hear yourself.” Sometimes – for example when I am doing certain sports – something will pop out my mouth (to myself) out of context; I guess this is my light or pre conscious talking. I guess Buddhists / meditationists / self-hypnotists are accessing their own deep unconscious if they are successful, too.