725 ILCS 5/104-10 : Rights and Remedies — Criminal Procedure — Code of Criminal Procedure of 1963 — General Provisions — Fitness For Trial, To Plead or To Be Sentenced —10 - Presumption of Fitness; Fitness Standard

A defendant is presumed to be fit to stand trial or to plead, and be sentenced. A defendant is unfit if, because of his mental or physical condition, he is unable to understand the nature and purpose of the proceedings against him or to assist in his defense.

725 ILCS 5/104-10

P.A. 81-1217.