For distinctness, we may consider habits, as belonging to the body, or to the mind: and the latter will be explained by the former. Under the former are comprehended all bodily activities or motions, whether graceful or unbecoming, which are owing to use: under the latter, general habits of life and conduct; such as those of obedience and submission to authority, or to any particular person; those of veracity, justice, and charity; those of attention, industry, self-government, envy, revenge. Habits of this latter kind seem produced by repeated acts, as well as the former. And as habits belonging to the body are produced by external _acts_, so habits of the mind are produced by the _exertion_ of inward practical principles; _i.e._ by carrying them into act, or acting upon them; the principles of obedience, of veracity, justice, and charity. Nor can those habits be formed by any external course of action, otherwise than as it proceeds from these principles: because it is only these inward principles exerted, which are strictly acts of obedience, of veracity, of justice, and of charity. So likewise habits of attention, industry, self-government, are in the same manner acquired by exercise; and habits of envy and revenge by indulgence, whether in outward act, or in thought and intention; _i.e._ inward act: for such intention is an act. Resolutions to do well, are also properly acts. And endeavoring to enforce upon our own minds a practical sense of virtue, or to beget in others that practical sense of it, which a man really has himself, is a virtuous act. All these, therefore, may and will contribute towards forming good habits. But going over the theory of virtue in one’s thoughts, talking well, and drawing fine pictures, of it; this is so far from necessarily or certainly conducing to form a habit of it, in him who thus employs himself, that it may harden the mind in a contrary course, and render it gradually more insensible; _i.e._ form a habit of insensibility to all moral considerations. For, from our very faculty of habits, passive impressions, by being repeated, grow weaker. Thoughts, by often passing through the mind, are felt less sensibly: being accustomed to danger, begets intrepidity, _i.e._ lessens fear; to distress, lessens the passion of pity; to instances of others’ mortality, lessens the sensible apprehension of our own.