I respectfully submit the principles here, for the first time expounded, as the foundation of a proper marriage relation, and a solution of the social problem. I now discuss the important question of age. There are great possibilities of good and evil involved in this branch of the subject, and nature's laws are violated in this as in every other department. The proper age for the consummation of marriage is maturity. This varies much in different constitutions and in different climates, but is not hard to determine. A general average for the temperate zone would place the proper age at from 22 to 27 in the male, and from 18 to 23 in the female. There are a thousand arguments against premature marriages, which I shall not stop to discuss in this lecture. You will hear this subject fully discussed in my lectures on Sexual Science, and you will also find it elucidated at length in my "Science of Creation." Those who have neglected to marry until past the ages above given, if in sound health and good character, may consider that they have my consent as soon as they can find a proper complementary consort, according to my full written delineation. The female should be about three years younger than the male. This rule applies at all stages of life. Under no circumstances should a man marry a woman older than himself. Neither should he marry one more than five years his junior; and three above stated is better, because the female matures three years younger than the male, as a rule, and this allows for both to marry at the same stage of maturity. There are most weighty physiological reasons for the support of this rule, the full discussion of which I reserve until my lectures on Sexual Science. But I will answer one common objection to this rule right here: It is quite a common belief that, unless a man marries a woman ten years his junior, in a few years his wife will look too old for him. This belief is based upon the fact that most married women break down and look old in a very short time. This is lamentably true, but there is no good reason why it should be so. It is contrary to nature, and whenever a result is contrary to nature, the cause which produces it is a violation of nature's laws; and the violation of nature's laws, which results in the premature decay of American women, is found mainly in improper marriages, wrong sexual conditions, unhygienic habits, and the woful ignorance of both husband and wife in all that pertains to a proper marriage relation. And, ladies, if you will see that your husbands attend my lectures on Sexual Science, I will promise to educate them to that point where they will be able to preserve your beauty. And in my lectures to ladies on the same subject, I shall impart knowledge which will aid you in preserving your charms and also increasing the manliness of your husbands.