on of sufficient and
well-defined premises, to warrant such inference. But where are these
materials to be found? There is a strong presumption that this
unsoundness remains an unsolved problem to the present hour, and it is
exemplified in the difference of sentiment that prevailed on a late
occasion,[B] between the most eminent of the medical profession; where
the same opinions and conduct impressed certain physicians, that this
nobleman was of sound mind, and others that his mind was thoroughly
unsound: so that the jury were to _proceed to make their inference_ from
the opposite testimony, deposed by the medical evidence, or to proceed
to hold such evidence in little esteem from its contrariety on a subject
which these physicians professed to illustrate. The term unsoundness,
applied to designate a certain state of the human mind, hitherto
undescribed, has not originated with medical persons; to them,
therefore, we cannot refer for the solution of its import, and there can
be no analogy between the definite unsoundness of animal and vegetable
substances, and any condition of the intellect. Timber is said to be
unsound, and although we may be little acquainted with the cause by
which it is produced, yet its actual state of rottenness is evident:--a
horse is unsound, in consequence of some morbid affection that can be
pointed out by the veterinarian:--a dentist can detect an unsound
tooth:--a physician, from certain well marked symptoms, concludes that
the lungs or liver of an individual are unsound:--particular doctrines
are held to be unsound, because they deflect from such as are orthodox,
and it is presumed there may be an unsound exposition of the law. The
human mind, however, is not the subject of similar investigation; we
are able to discover no virus by which it is contaminated--no spreading
rottenness--no morbid leaven that ferments, or canker that corrodes it.

Although we may apply the word unsoundness, in a figurative or
metaphorical sense, to the human mind, yet we cannot detect in it any of
the marks or indications that characterize the unsoundness of substances
acknowledged to be in that state: it is, therefore, under this
conviction, and with the view of increasing our knowledge of the human
intellect, that, on the behalf of the members of the medical profession,
I venture to solicit your Lordship, on the first opportunity that may
occur, to elucidate the nature of this UNSOUNDNESS OF MIND, so that
physi