Sufficient explanation

Most of our formidable maladies are rare, but insanity is unfortunately not only frequent but said to be peculiarly endemic to England; nor are we left to conjecture the causes. Early dissipation, unrestrained licentiousness, habitual luxury, inordinate taste for speculation, defective systems of education, laxity of morals; but more especially, promiscuous intermarriages where one or both of the parties have heriditary claims to alienation of mind, are sufficient to explain the lamentable fact.

C***
Practical Observations on Insanity, p. v.