Bharatiya Nyaya Sanhita, 2023 · Chapter III: General Exceptions
Section 22: Act of a person of unsound mind
In plain words
An act is not an offence if, at the time, the person was of unsound mind and so could not know what they were doing, or that it was wrong or against the law.
- The test is the person's state of mind at the moment of the act, not before or after.
A simplified explanation, prepared with AI assistance from the official text below and checked automatically against it for numbers and cross-references. The official text is the law and prevails over this summary. Not legal advice.
Read the in-depth explanation, with key Supreme Court rulings ↓
Official text
Nothing is an offence which is done by a person who, at the time of doing it, by reason of unsoundness of mind, is incapable of knowing the nature of the act, or that he is doing what is either wrong or contrary to law.
Corresponding sections were matched by comparing the wording of both official texts, and for the IPC and BNS, also against a published correspondence table. Wording, punishments and structure often changed, so read both sections before relying on the match.
Source: India Code (indiacode.gov.in), the consolidated text published by the Legislative Department, Government of India. Text as updated on India Code on 25 August 2026. Words in square brackets [ ] were inserted or substituted by later amending Acts, and *** marks words omitted by an amendment. The amendment footnotes are not reproduced here. Official text on India Code.
Understanding this section
Section 22 carries forward section 84 of the IPC word for word: the insanity defence. A person who, at the time of the act, was incapable because of unsoundness of mind of knowing its nature, or that it was wrong or contrary to law, commits no offence.
Key points
- The test is legal insanity, not a medical diagnosis.
- The relevant moment is the time of the act; behaviour before, during and after is evidence of it.
- The accused's burden is on a balance of probabilities, and evidence that falls short may still raise reasonable doubt about intent.
- The IPC case law applies fully.
Key Supreme Court rulings
Dahyabhai Chhaganbhai Thakkar v. State of Gujarat AIR 1964 SC 1563
Decided under section 84 of the IPC. There is a "rebuttable presumption that the accused was not insane"; the accused's burden is no higher than in civil proceedings, and evidence of insanity may still create reasonable doubt that leads to acquittal.
Surendra Mishra v. State of Jharkhand 2011 INSC 17
Decided under the IPC. Conduct such as threatening a witness, fleeing and hiding the weapon showed the accused knew the act was wrong, so the defence failed.
Common mistakes
- Treating mental illness as automatically equal to legal insanity.
Read with: Section 23 BNS, Section 84 IPC
Prepared with AI assistance as a study aid. Every ruling listed was checked against the Supreme Court's own judgments on this site, and quoted words appear in those judgments; linked names open the full judgment. Read the judgments themselves before relying on them. Not legal advice.
Supreme Court judgments citing the section 22
No Supreme Court judgment in our database cites this section yet.