The earliest friendships, the friendships which are naturally contracted when the heart is most susceptible of that feeling, are those among brothers and sisters. Their good agreement, while they remain in the same family, is necessary for its tranquillity and happiness. They are capable of giving more pleasure or pain to one another than to the greater part of other people. Their situation renders their mutual sympathy of the utmost importance to their common happiness; and, by the wisdom of nature, the same situation, by obliging them to accommodate to one another, renders that sympathy more habitual, and thereby more lively, more distinct, and more determinate. The children of brothers and sisters are naturally connected by the friendship which, after separating into different families, continues to take place between their parents. Their good agreement improves the enjoyment of that friendship; their discord would disturb it. As they seldom live in the same family, however, though of more importance to one another than to the greater part of other people, they are of much less than brothers and sisters. As their mutual sympathy is less necessary, so it is less habitual, and therefore proportionally weaker. The children of cousins, being still less connected, are of still less importance to one another; and the affection gradually diminishes as the relation grows more and more remote. What is called affection, is in reality nothing but habitual sympathy. Our concern in the happiness or misery of those who are the objects of {195} what we call our affections; our desire to promote the one, and to prevent the other; are either the actual feeling of that habitual sympathy, or the necessary consequences of that feeling. Relations being usually placed in situations which naturally create this habitual sympathy, it is expected that a suitable degree of affection should take place among them. We generally find that it actually does take place; we therefore naturally expect that it should; and we are, upon that account, more shocked when, upon any occasion, we find that it does not. The general rule is established, that persons related to one another in a certain degree, ought always to be affected towards one another in a certain manner, and that there is always the highest impropriety, and sometimes even a sort of impiety, in their being affected in a different manner. A parent without parental tenderness, a child devoid of all filial reverence, appear monsters, the objects, not of hatred only, but of horror to their neighbours.