Sound Mind / Or, Contributions to the natural history and physiology of the human intellect

Dear Sir,
The privilege of long acquaintance, and a sufficient experience of the kindness of your disposition, might be an adequate inducement to dedicate the following pages to your notice. To this offering, I am however impelled by motives, which boast a higher descent, and more enlightened character:—an admiration of your superior talents, and the adaptation of those excellent endowments, to the advancement and happiness of the human race,—and by which you have been enabled
The applause of listening senates to command.
The subjects to which I now solicit the permission of prefixing your name, were once your favourite study; and I am induced to consider your profound researches into the nature and constitution of the human intellect, as the basis of that high reputation, you now so deservedly maintain among the wise and dignified of your contemporaries.
I am, Dear Sir, with respect, esteem, and the kindest feelings, Your very obedient servant, JOHN HASLAM.

The indulgence of the public has been already extended to several works which I have submitted to its decision on the subject of Insanity; and the same favourable interpretation is now solicited for the present performance,—which attempts the more difficult investigation of Sound Mind. In treating of Mental Derangement, I became very early sensible, that a competent knowledge of the faculties and operations of the Intellect in its healthy state, was indispensably necessary to him, who professed to describe its disorders:—that in order to define the aberrations, the standard should be fixed. There was indeed no lack of theories and systems of Metaphysic; and although they essentially differed, many possessed the highest reputation. Amidst this distraction of conflicting opinions, which no mediator could adequately reconcile,—without daring to contend with a host of discrepancies, or presuming to demolish the lofty edifices which scholastic Pneumatology had reared,—I determined to throw off the shackles of authority, and think for myself. For it was evident, on the freehold ground of literature, that there is ample room and verge enough for every man to build his own tenement;—and the present construction is too lowly to intercept another's prospect, and without those ornaments that might provoke the jealousy, or challenge the rivalship of surrounding inhabitants.