One way to contest a will in Tennessee is to assert that the decedent had a “lack of testamentary capacity”. Basically, this is an assertion that the individual who executed the will was not actually competent to execute the will. Tennessee has many cases that discuss this claim in the context, most often, of a will contest situation.
The Tennessee Court of Appeals has said the following about what is required to establish “lack of testamentary capacity” contest to a will:
The law requires that the testator’s mind, at the time the will is executed, must be sufficiently sound to enable him or her to know and understand the force and consequence of the act of making the will. American Trust & Banking Co. v. Williams, 225 S.W.2d 79, 83 (1948). The testator must have an intelligent consciousness of the nature and effect of the act, a knowledge of the property possessed and an understanding of the disposition to be made. Goodall v. Crawford, 611 S.W.2d 602, 604 (Tenn. App. 1981). While evidence regarding factors such as physical weakness or disease, old age, blunt perception or failing mind and memory is admissible on the issue of testamentary capacity, it is not conclusive and the testator is not thereby rendered incompetent if her mind is sufficiently sound to enable her to know and understand what she is doing. American Trust, supra; 79 Am.Jur.2d Wills § 77 (1975).