Every person of sound mind not being a minor may dispose of his property by will.
Explanation 1.- A married woman may dispose by will of any property which she could alienate by her own act during her life.
Explanation 2.- Persons who are deaf or dumb or blind are not thereby incapacitated for making a will if they are able to know what they do by it.
Explanation 3.- A person who is ordinarily insane may make a will during interval in which he is of sound mind.
Explanation 4.- No person can make a will while he is in such a state of mind, whether arising from intoxication or from illness or from any other cause, that he does not know what he is doing.
Illustrations:
(i) A can perceive what is going on in his immediate neighbourhood, and can answer familiar questions, but has not a competent understanding as to the nature of his property, or the persons who are of kindred to him, or in whose favour it would be proper that he should make his will. A cannot make a valid will.
(ii) A executes an instrument purporting to be his will, but he does not understand the nature of the instrument, nor the effect of its provisions. This instrument is not a valid will.
(iii) A, being very feeble and debilitated, but capable of exercising a judgment as to the proper mode of disposing of his property, makes a will. This is a valid will.
Explanation 2.— Persons who are deaf or dumb or blind are not thereby incapacitated for making a Will if they are able to know what they do by it.
Explanation 3.— A person who is ordinarily insane may make a Will during interval in which he is of sound mind.
Explanation 4.— No person can make a Will while he is in such a state of mind, whether arising from intoxication or from illness or from any other cause, that he does not know what he is doing.
Legal Commentary & Landmark Judgments: Section 59
Section 59 establishes the statutory criteria for testamentary capacity, requiring that every person of sound mind not being a minor may dispose of his property by will.
A married woman under Explanation 1 is fully competent to dispose by will of any property which she could alienate by her own act during her life.
Explanations 2, 3, and 4 provide crucial legal standards: deaf, dumb, or blind persons can make valid wills if they know what they are doing; a person who is ordinarily insane may execute a valid will during a lucid interval (Explanation 3); and no person can make a will while in such a state of mind, whether arising from intoxication, illness, or other cause, that they do not know what they are doing (Explanation 4). A sound disposing mind requires the mental capacity to comprehend the nature of the act, the extent of the property being disposed of, and the claims of natural heirs whom the will favors or excludes.
Testamentary capacity under Section 59 is the primary battleground in probate challenges involving elderly testators. Litigators should understand that eccentricity, physical paralysis, or severe bodily disease does not equate to mental incapacity. The critical evidentiary moment is the exact date and hour of execution. Practitioners preparing wills for elderly or ailing clients should proactively obtain a contemporaneous certificate of mental fitness from an independent qualified physician and capture video footage of the execution to create an unshakeable evidentiary record.