The answer is: Carl rogers
Unconditional positive regard Refers to the act of showing full support and conditional love to another person regardless of that other person did or said.
Carl rogers was one of the major supporter in implementing unconditional positive regard in therapy session. He believed that showing full support to the patient provide the perception that the session is a safe space for the patient to fully let out the things on their mind.
He argued that this method would make it easier for psychologists to identify the disorder that the patient had and help the therapists to prepare the proper treatment to address the disorder. In the long run , this would bring positive regard in healthy personality development.