This is the house of brethren, kindred; neighbours, cousins; short inland journeys, letters, messages, rumours, and the removal of trade or employment. From this house the ancient Astrologers derived their judgment, relative to the kindred or brethren of the native, born under any particular horoscope, with the good or bad fate attending them; and also of those particular changes which were perpetually recurring throughout life; in which particular they were accustomed to judge by the lords of the house, and triplicity, according to that sign or constellation of heaven which was found on the cusp, great part of which judgment can scarcely be relied upon; but when malefic or unfortunate stars, are located in this house, or in mundane square, semisquare, or opposition thereto, the attentive student will readily perceive appropriate evil effects, corresponding to the significations of the house above described, thus Saturn being there, is generally found to cause hatred and ill-fortune through brethren, neighbours, and short journeys - Herschel there, never permits the native to rest long in one place, or to meet with mutual affection from his kindred; but Mars afflicted in the third bouse is said by the ancients to be "the very demon of discord and genius of ill luck in all things to which the house has relation". The good planets of course have benign effects, most palpably visible.

In horary questions, every signification, of the house is allowed in its full symbolical allusion, for in such cases the indication will no doubt be complete: hence all questions relative to the aforesaid subjects, are judged as well by the lord of the house, as the accidental positions and configurations thereto. In addition to those descriptions, the following are manuscript; "Zael", an Arabian writer of great repute, sets forth the third house as denoting " sects, epistles, dreams, mutation, churches, clerks, carols, changing of women from place to place, etc. being the fourth house, as reckoned in order from the twelfth, it signifies the fathers of private enemies, the sons of friends being the fifth to the eleventh house; also the sickness of kings, for it is the sixth house from the tenth or mid-heaven; also the enemies of religious persons, for it is the seventh house, or opposite to the ninth; as well as the magistery (or trade) of servants, as being the tenth house to the sixth; and the friends of children, being the eleventh house to the fifth; and the private enemies of the father, as being the twelfth house in order from the fourth house".

It is a masculine house, and similar to II, ruling the arms, hands, and shoulders.