LAW OF EVIDENCE 635
(iii) Disease of the mind
This contemplates the case of an idiot and a lunatic, both suffer from the disease of the mind.
An idiot is one who is born irrational, without the reasoning faculty. A lunatic is one who is born rational, has subsequently become irrational and lost his reasoning faculty.
A lunatic is either a monomaniac or is a maniac for the time being. That being so, a lunatic is not incompetent merely because he is a lunatic. Lunacy does not mean complete annihilation of understanding. If it is general lunacy, he may be lucid at intervals. If he is a monomaniac, his understanding about other matters may be clear.
Illus. of partial lunacy.
(1) Murder discussion in Lunatic Asylum.
(2) Interview by a person with his lunatic friend in the asylum and his remark about time.
Illus. of Monomaniac
(1) R. V. Hill—Hill was tried for murder. Donelly witness— lunatic—suffered from the delusion that he had 20000 spirits about him which were continually talking to him.
That being so a lunatic can be a competent witness.
This is recognized in the Explanation.
(iv) Any other cause.
This means any other cause depriving a person of his power of understanding. e.g. drunkenness.
Some of these disabilities are coextensive with the cause, therefore, when the cause is removed the witness becomes competent.
e.g. When pain ceases drunkenness ceases Lunacy ceases
Whether there is understanding or not in the witness, is a matter which is determined by the Court by questioning the witness.