Haw. Rev. Stat. § 704-403: Physical or mental disease, disorder, or defect excluding fitness to proceed.

No person who as a result of a physical or mental disease, disorder, or defect lacks capacity to understand the proceedings against the person or to assist in the person's own defense shall be tried, convicted, or sentenced for the commission of an offense so long as such incapacity endures.

COMMENTARY ON §704-403

The section sets forth the universally accepted position in Anglo-American law that a defendant cannot be proceeded against (with the exception of being charged) unless the defendant has the capacity to understand the proceedings against the defendant and assist in the defendant's own defense. The Code deliberately avoids terms such as "the then present insanity"[1] and focuses on those factors which call for a suspension of the proceedings: (1) lack of capacity to understand the proceedings, or (2) lack of capacity to assist in the defense.