Alfred Adler's "individual psychology"

アドラー「人生の意味の心理学」
アルフレッド･アドラー(1870-1937）
すべての人は対等な関係にある

I noticed that his "psychology" is very popular in Japan. I recently watched a TV Program that introduced his "individual psychology". It was very interesting. I have not read any books written by him.