Section 175: Who may testify.

1 All persons shall be competent to testify, unless the court considers that they are prevented from understanding the questions put to them, or from giving rational answers to those questions, by reason of tender years, extreme old age, disease, whether of body or mind, any other cause of the same kind.

2 A person of unsound mind is not incompetent to testify, unless he is prevented by his mental infirmity from understanding the questions put to him and giving rational answers to them.