How much sex is appropriate varies from one couple to the next. But one thing I think should be a hard and fast rule is that sex should be practiced as a healing entity rather than a means of escaping emotional trauma or engaging in negative behavior driven by subconscious motivations.
The amount of and type of sex that people engage in will vary as much as the amounts and types of foods that people eat. What's extremely important, though, is that a person's sex life is conscious. An example of when sex gets out of context is if one participates in it too much because they’re motivated by a desire for relief from anxiety.
It should be quite clear that at times some degree of sexual abstinence is necessary. Sometimes abstinence might be warranted when one of the partners is engaging in sex too much to escape their emotional discomfort. Sometimes one of the partners might just need some “space.” At other times one of the partners might not be feeling well physically and in such cases will need to be left alone for a time.
While sex will likely feel good for two consenting adults, some may have severe trauma associated with it. It's beyond the scope of this book to address those types of issues. People with sexual dysfunction resulting from traumatic experiences will need to engage in intensive counseling and other corrective measures.
All people will have emotional and psychological issues that will complicate their sex lives to some degree. But those issues can be overcome. It may not be necessary for most people to have to seek professional help to overcome sexual difficulties. But all people who engage in sex should do so out of love for their partners and have a healthy respect for the degree to which sexual encounters are intertwined with higher consciousness.