自白，一個讓人既擔心其遭濫用，卻又割捨不下，而不斷加重其功能與角色的概念。自白除具有證據、簡化程序的功用外，亦在刑罰裁量上扮演重要角色。尤其，在實務迅速結案的需求下，法院和被告間產生自白和減刑的對價關係，以謀求程序的簡化。然而，此一自白減刑理由，必須在實體量刑理論上獲得支持，否則即是提供被告法所不容許的不正利益。依照本文研究的觀點，只有出於悔悟與認罪動機的自白，才能作為量刑上有利行為人的犯罪後之態度。不過，由於悔悟動機的調查困難，配合罪疑唯輕原則的適用結果，則是除證明被告的自白非出於悔悟與認罪提出者，自白將納入減刑考量。就此來說，只求訴訟經濟，而不顧及被告自白動機的立法與司法實務，值得檢討。

The confession is a legal concept which on one hand may generate concerns of possible abuse and on the other hand is indispensible and at the same time continuously gains its importance with respect to its role and function in criminal justice. Besides its evidentiary function and simplifying trial procedure function, a confession plays a significant role in the court’s exercising its discretion on sentence. Especially when there is a demand of speedy trail in practice, there is a consideration relationship between the court and the accused in order to simplify the trial procedure. However, there must be a theoretical support of substantive sentences before a confession can be utilized to reduce criminal penalties; otherwise, the court indeed illegally confers the accused unjust interests. This Article contends that only those confessions which are made under the motives of genuine regrets and confession can be qualified as grounds for the reduction of criminal punishments under the sentencing factor of post-crime attitudes. But owing to the practical difficulty of ascertaining the regrets and confessions, coupled with the application of the principle that the benefit of doubt goes to the accused, unless the prosecutor can prove the confession of the accused was not made under the motives of genuine regrets and confession, the court shall take it into account. According to this point of view, the current substantive and procedural law and practice which take the confession of the accused regardless the underpinning motives of genuine regards and confession shall be subject to review.