4221. How it is that from habit or actuality such a result is produced appears from a variety of similar things in regard to which a man is not aware that they are contracted by habit, as for instance his speaking, his eating or chewing, his walking, all which a man learns, and without learning could not do them. So it is also in respect to the avoidance of objects in one's way, the perception of the quality of others from their speech and face, and the motion of the arms; in fact, the case is the same in relation to all the senses, that certain results are contracted by habit which, from their being so familiar, one is not aware that they pertain to him. - 1749, April 15.