Suicide and murder
Suicide is seen as a desirable thing in this book. The constant plagues of paranoia, fame, and the FBI make Tender even more tender to pain and scrutiny. He often murders people instead of committing suicide, but they are not all that different it seems. He feels that suicide is his destiny and fate, but then in the end, when he is the last survivor of the suicide cult, he admits that he learned a way to escape the plane. The author says on his website that he actually survives. He is not even suicidal. He is just murderous.
Schizophrenic reality
In the end, this novel should be regarded as a work of art and fiction, because its attempts to explain insanity deviate quite substantially from what the actual psychology suggests. But, as a novel, the use of schizophrenia is symbolic and thematic, because it points to the truth that all humans are subject to their interpretive faculties, and when someone stops perceiving reality in the plain, normal way, they begin experiencing some other self, it seems from the book. This is symbolized by Adam, whose name is a reference to religion, because Adam is the first man and the first man to sin. By blaming Adam, he fails to accept responsibility for his free will and choices.
Birth and death
The life cycle is seen in Tender's relationship to Fertility, whose very name is an homage to this theme. By invoking the theme of child birth and pregnancy, and then by Tender's successful murder of his sister, it can be seen that his moral evil is that he interrupts the life cycle of birth and death by being willing to murder. Although he imagines it is Adam doing it, he knows he is the real killer. He figures it out when he realizes that he couldn't have read about himself in the paper before the hijacking happened.
