From the observations which have been detailed concerning unsoundness of mind there is, according to legal construction, an evident connection between unsoundness and imbecility. My object, however, is not the interpretation of law, but the exposition of nature and fact. It alone interests me to describe the phœnomena of mind—to compare the performance of its offices in a sound and morbid state—and to measure by the accredited standard of common sense and intelligible reasoning, the degree of imbecility, inability, or incapacity, which disqualifies an individual to conduct himself and manage his affairs. The necessity of legal interference and protection in cases of insanity, having been sufficiently adverted to; it now remains to shew that a person from imbecility of mind may be equally incompetent to the management of himself and affairs. The mind may be weak from birth, or it may at any period of life become enfeebled by disease. Like the body it has its regular periods of growth and development, of maturity and declension: but they are not periodically connected. An unusual precocity of mental vigour has been occasionally remarked; and in advanced age the wisdom of the man frequently survives the infirmities of the body. Men are relatively competent, wise or foolish, learned or ignorant, compared with others. On the scale of intellectual being, we may place the philosopher at the summit, at the bottom the degraded ideot: and in the population of this world the intermediate range is adequately filled up. There are many considerations which demand attention on this important subject. To state that certain acquirements were to be attained as the proof of competency, would be an imperfect criterion. Much might be acquired _memoriter_, which the learner would not understand: a very feeble intellect, insufficient for the purposes of human affairs, might be trained to answer correctly a string of known questions, without being able to comprehend or adapt them to any useful purposes. It should likewise be considered that the different departments of employment require very different degrees of mental capacity. A person might be able to manage duly a small income, who would be inadequate to the distribution of a large revenue: a man might be competent to keep a shop, who would become overwhelmed and distracted in the learned professions: a country squire might gallop hospitably through life, without being able to discharge his duty as a magistrate. It is not the want of acquirement that should disqualify an individual; many persons from distaste, indolence, from neglect of parents and guardians, remain lamentably ignorant in the current acceptation of the words—they are unable to write or read, they are unacquainted with the symbols which represent numbers: yet with these deficiencies they are enabled to conduct themselves in the world. Speech itself is not absolutely necessary;