Who developed a therapy technique that requires a patient to explore their real and ideal selves?

Carl Rogers was a humanistic psychologist who lived throughout the 20th century. He supported the idea that in order for a person to develop, they need an environment that provides them:

Genuineness: To behave with openness towards others. Acceptance: Being to see ourselves in a continuous positive way. Empathy: The chance of being listened to and understood.

He developed the concept of "self-actualization", which occurs when a person's ideal self is highly represented in his o her current behavior (real self).