If you want to understand Chesterton and his spiritual and philosophical thought, start with his book "Heretics" (1905), follow up with "Orthodoxy" (1908), go through many other works, and finish up with "The Well and the Shallows" (1935) and this book (1935 or 1936).
In "Heretics," Chesterton discussed and criticized the distortions of traditional Christianity, and in "Orthodoxy," he explained (very clearly and wittily) how and why he found himself on the side of traditional 2000-year-old Christianity.
In "The Well and the Shallows" Chesterton - by then having "crossed the Tiber" to Rome, defended the position that Roman Catholicism was the source of all that was admirable in the civilization of the Middle Ages (a position held also by historians such as Christopher Dawson, R. W. Southern, and Régine Pernoud).
In "The Thing" Chesterton describes how and why he himself became a Catholic, even though it cost him; he argues that one cannot argue against Truth when one finds it.
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Here are a few snippets defending the traditional family:
"Among the traditions that are being thus attacked, not intelligently but most unintelligently, is the fundamental human creation called the Household or the Home. That is a typical thing which men attack, not because they can see through it, but because they cannot see it at all. They beat at it blindly, in a fashion entirely haphazard and opportunist; and many of them would pull it down without ever pausing to ask why it was put up."
"Some social reformers try to evade this difficulty by some vague notions about the State or an abstraction called Education eliminating the parental function. But like many notions of solid scientific persons, it is a wild illusion of the nature of mere moonshine."
"The existing and general system of society, subject in our own age and industrial culture to very gross abuses and painful problems, is nevertheless a normal one. It is the idea that the commonwealth is made up of a number of small kingdoms, of which a man and a woman become the king and queen and in which they exercise a reasonable authority, subject to the common sense of the commonwealth, until those under their care grow up to found similar kingdoms and exercise similar authority. This is the social structure of mankind, far older than all its records and more universal than any of its religions; and any attempts to alter it are mere talk and tomfoolery."
