no one can be a poet without a certain unsoundness of mind.
Examples of unsoundness
unsoundness
Why was CLASS included in Obamacare despite its actuarial unsoundness?
From the forbes.com
Abnormal discoloration of wood often denotes a diseased condition, indicating unsoundness.
From the en.wikipedia.org
Demonstrating the unsoundness of the philosophical basis for religion was an important aim of Hume's writings.
From the en.wikipedia.org
Nauruans may not be deprived of the right to vote on the grounds of unsoundness of mind, nor due to being in gaol.
From the en.wikipedia.org
Bailey said that until such baseline science is conducted, the industry will just be guessing at the causes of unsoundness.
From the courier-journal.com
There are other issues, I suspect, where the candidates may have more room for doctrinal unsoundness than they seem to think.
From the economist.com
The school's two-storey 1920s brick buildings were pulled down and replaced in 1961, because of their structural unsoundness.
From the en.wikipedia.org
With fewer stallions being bred to record numbers of mares, the result is a dilution of the gene pool and reinforcement of unsoundness traits, many say.
From the courier-journal.com
More examples
A condition of damage or decay
A misconception that is fallacious and not true or valid; "the unsoundness of his conclusion was obvious"
Not mentally or physically healthy; "no one can be a poet without a certain unsoundness of mind"
The state of being unsound
Any condition that prevents a part of the body from maximal function.
A structural weakness that affects the normal movement or use of the horse.
Any defect or injury that interferes with the usefulness of an animal.