Final answer:
Existential therapy embraces the values of authenticity, meaning, and self-determination, but not isolation.
Step-by-step explanation:
Existential therapy embraces three values: authenticity, meaning, and self-determination. The value that is not embraced by existential therapy is isolation. Existentialism emphasizes individual existence, freedom, and choice, and it is grounded in the belief in human freedom. Isolation, on the other hand, is not a value that existential therapy promotes.