A person shall be criminally liable only when committing an act intentionally, except when committing an act by negligence in a case where the law provides that such person must be liable when acting by negligence, or except in a case where the law clearly provides that such person must be liable even when not acting intentionally.
To commit an act intentionally means to do an act consciously and at the same time the doer desires or could have foreseen the consequence of such act.
If the doer does not know the facts constituting the elements of the offence, it cannot be deemed that the doer desired or could have foreseen the consequence of such act.
To commit an act by negligence means to commit an offence unintentionally but without exercising such care as might be expected of a person in such circumstances and condition, and the doer could have exercised such care but did not do so sufficiently.
An act shall include any consequence brought about by the omission of an act which must be done in order to prevent such consequence.
Section 59 establishes the fundamental principle that criminal liability requires intent (mens rea). This is the cornerstone of Thai criminal law — no person shall be criminally liable unless acting intentionally. Negligence is punishable only when the law specifically provides.
This section has remained largely unchanged since the Code's enactment in B.E. 2499 (1956), reflecting its enduring importance as a constitutional-level protection in criminal law.
In every criminal case, the prosecution must prove intent beyond reasonable doubt. Defense attorneys frequently rely on Section 59 to argue lack of criminal intent.
The Santika nightclub fire case, in which sixty-six people died during a New Year's celebration when indoor fireworks ignited flammable decorations. The Supreme Court reaffirmed corporate criminal liability for negligent killing under Section 291. The company that installed the pyrotechnics was found criminally liable alongside its directors. This case reinforced that businesses operating entertainment venues have a duty of care, and corporate negligence causing mass casualties will result in criminal prosecution.
The defendant was riding a motorcycle with the victim as passenger. After an accident, the victim was unconscious with serious injuries. The defendant abandoned the victim at the roadside for 8 days without seeking medical help. The Supreme Court held that where a person causes injury to another and then deliberately abandons the victim knowing that death may result from the failure to act, this constitutes attempted murder by omission under Sections 288 and 80.
The defendant used a firearm to shoot the victim with intent to kill, but when the victim dodged, the bullet penetrated and hit another person by accident. The Supreme Court applied the transferred intent doctrine under Section 60 (aberratio ictus), convicting of attempted murder by mistake. This case confirmed that when a perpetrator aims at one person but hits another due to the victim's evasion, the transferred intent provisions of Section 60 apply, treating the harm to the unintended victim as intentional.
The defendant fired a gun into a crowd in a confined space. The Supreme Court held that shooting into a crowded area where people are gathered closely together constitutes intent to kill by foreseeability (Section 59, paragraph 2). Even if the defendant did not aim at a specific individual, shooting into a crowd demonstrates that the defendant must have foreseen that death could result from the act.
A liquid gas explosion at a commercial establishment killed ninety people. The Supreme Court extended corporate criminal liability to negligent crimes under Section 291, holding that the managing partner's negligence in maintaining safety standards was attributable to the company. This case confirmed that corporate entities can be criminally liable for negligent acts, not just intentional offences.
The defendant fired a weapon into the victim's home at night. Although the bullets did not strike the victim, one landed approximately 1 meter from the victim and another struck beneath a window. The Supreme Court applied the doctrine of constructive intent (เจตนาเล็งเห็นผล) under Section 59, reasoning that a reasonable person would foresee that firing into an occupied home at night would endanger its inhabitants. This landmark case established the standard for inferring intent to kill from the circumstances of the act.
The defendant shot at his daughter-in-law during a dispute, but the bullet struck a mango tree 5 meters away. The court found significant doubt regarding intent to kill, noting the defendant held the gun at waist level with both hands rather than aiming, and at close range an intentional shooter would likely not miss. The defendant had a habit of using firearms to threaten. The court applied the principle of benefit of doubt in favor of the defendant, establishing that mere firing a weapon does not automatically prove intent to kill.
The defendant repeatedly struck the victim on the head with a blunt instrument during an exorcism ritual, causing death. The Supreme Court held that repeated blunt force trauma to a vital area such as the head constitutes constructive intent to kill (เล็งเห็นผล) under Section 59, even where the defendant claims the purpose was spiritual. The Court ruled this was murder under Section 288, not mere negligent homicide, because a reasonable person would foresee that such acts would likely cause death. Religious belief is not a defense to murder in Thailand.
Disclaimer: The English translation is unofficial and for informational purposes only. The authoritative text is in Thai as published in the Royal Thai Government Gazette (Ratchakitchanubeksa).ข้อสงวนสิทธิ์: คำแปลภาษาอังกฤษเป็นคำแปลอย่างไม่เป็นทางการ เพื่อวัตถุประสงค์ในการให้ข้อมูลเท่านั้น ข้อความที่เป็นทางการเป็นภาษาไทยตามที่ประกาศในราชกิจจานุเบกษา