本文含三部份。第一部份描述作者如何起意、尋找、界定與應用「習慣」概念之心路歷程。第二部份描述作者如何修改習慣之舊定義，使其更適用臨床心理學研究與臨床服務工作，也根據習慣定義與已有的習慣分類方法對心理衛生學及心理治療學下了新定義，並根據習慣定義訂定習慣改變之四大策略，並試將當今已存的心理治療技巧分類到適當的改變策略中。 第三部份則討論習慣定義和心理衡鑑、心理測驗的關係，以及編製習慣測驗之要領與重要性。 本文強調習慣概念的應用範圍頗大，非常適用於心理衡鑑與心理治療兩大領域。應用於前者時，此概念可助臨床心理師擴大其關心範圍，帶他走出以變態為重的醫學診斷模式，而走入兼顧健康與病理兩面的「全人診斷模式」。應用於後者時，此概念可擴大臨床心理師的視野，多關心當事人整體性的福利問題，不在僅汲汲於消減其心理症狀、痛苦情緒的「悲」之工作，也能做更多提升其快樂、幸福的「慈」之善行。易言之，能善用習慣概念於心理治療工作時，臨床心理師可成為「既能悲又能慈」的全人性化助人工作者。 附帶地，本文也指出新習慣定義給臨床心理學帶來多項正向衝擊；其一是根據習慣分類可發展出心理治療分類學，其二是根據習慣概念新定義及習慣改變的需要，將來臨床心理師可編製一系列甚具臨床價值的習慣測驗，以利心理診斷與治療工作。

In the present paper, my journey of habit psychology is narrated, I first describe how my motive was incited to search for a key concept necessary for clinical work, research and teaching in Taiwan, then how I stared to use the concept of habit, and finally, how and why I changed the defintion of "habit" to "a stable relation between the stimulus and the response." The second part of the present paper described how I redefined the concepts of mental health, psychodiagnosis, and psychotherapy all in term of habit. Four strategies of psychotherapy could be derived logically based on the new definition of habit: changing the stimulus, changing the connection between the stumulus and the response, changing the response, and changing the relationship between the target habit and other habits or habit patterns. Most psychotherapeutic techniques available today could be classified into one of the four afore mentioned therapeutic strategies. The main aim of the present author is to demonstrate that the concept of habit is so elastic that it is able to organize all theories of psychotherapy in one system under the concept and to allocate to each therapeutic technique a position most suitable for it. In the third part of this article, I explored the possiblity of applying the concept of habit to psychodiagnosis and developing a variety of tests for clinical as well as non-clinical work. Several habit tests have been developed for research purpose. These include a study habit scale and scales of anxious depressive, obsessive compulsive, antisocial and schizophrenic thinking habit.