unsoundness of mind

With these words he concludes one of his books: Perhaps no person can be a poet, or even can enjoy poetry, without a certain unsoundness of mind.

From Time Magazine Archive

Nothing is more confusing to the ordinary juryman than trying to determine the probative value of evidence touching unsoundness of mind, and the application thereto of the legal test of criminal responsibility.

From Courts and Criminals by Arthur Cheney Train

Already he had given abundant proofs of his courage, of his capacity, and of that strange unsoundness of mind which made his courage and capacity almost useless to his country.

From The History of England, from the Accession of James II — Volume 2 by Thomas Babington Macaulay, Baron Macaulay

Here a difficulty presents itself, which we must explain at once, namely, how can there be unsoundness of mind at all?

From Moral Principles and Medical Practice The Basis of Medical Jurisprudence by Charles Coppens

Now there is a great difference between inability to manage a man's affairs, and imbecility of mind taken as evidence of unsoundness of mind.

From A Letter to the Right Honorable the Lord Chancellor, on the Nature and Interpretation of Unsoundness of Mind, and Imbecility of Intellect by John Haslam