So what we understand as the "teachings of Buddhism" are not the teachings. They are merely the opening gambit of a dialogue between individuals.
What the Buddha says to someone depends on what he knows that person's capacity to understand is. As we listen in we may be confused.
The Buddha is not speaking in absolutes so much as he is administering exactly the medicine this person needs to be cured of delusion and the suffering that comes with it.
"Buddhism," rather than teaching dogma, is a path of practice to directly realize the liberating-truth the Buddha himself had found. What he knew, we can know. Less useful is belief or faith when insight-knowledge and wisdom are what set us free.
The Buddha's message is consistent, but that only emerges over time. He taught for 45 years. In any specific instance, what he is teaching may sound like a paradox or, worse, a tautology (some self-evident piece of circular logic).
However, when we recognize the dialectic pattern, it suddenly makes sense. It is perfect just as it is -- so long as it is grasped properly.
Buddhism has developed and become something different, the growth of a seed the Buddha planted. Some later schools may have gone too far afield, but they tend to return. Nagarjuna's "Middle Way" (Madyamika) philosophy brought this method of dialogue to an extreme in an attempt to counter clinging to views.
Theravada, the earliest existing Buddhist school, has a threefold division of the Dharma. Beginning as a living oral tradition, it was eventually written down. Then commentaries also had to be written down to explain what was missing in the absence of a living dialectic.
Many sutras may seem unbearably monotonous. This is because what was written down was for chanting to be listened to, not read the way we read books. The written parts were lists, formulas, rote memorization and mnemonic devices for oral teaching.
The real reason the Buddha singles out desire (tanha, craving) is not merely dialectical, as Watts suggests. Desire is NOT the ultimate cause of suffering, ignorance is. And enlightenment is the ultimate solution. Craving is one of the proximate causes. But it is the weak link in the chain of Dependent Origination. The Buddha saw it. He recognized it as an escape from suffering, because wisdom can uproot craving when what we crave is seen as it truly is. We can see it and uproot it with insight (vipassana). Willpower, rationalizing, and psychological suppression do not work. Serenity and insight do work.
The unbroken oral tradition remains, but it is rare and usually available only in monastic and meditative settings, which are open to non-monastic and temporarily ordained practitioners. The instructions are not secret, but they are also not printed all over books, which would place them out of context.
However, most monastics or "professional clergy" as Alan Watts refers to them, seem to be involved in chanting and formalities. They do not seem to be involved in the living teaching or practice for the goal the Buddha set out and created monasticism to support. They see their function as preserving the Dharma, sadly, without reaching the goal or being able to effectively guide others to that knowledge-and-vision of nirvana.
The Buddha's words were organized into chants and written in so formal a way that no person would have ever spoken. What was said was converted to this form. And if we cling to the form, we will miss the meaning.
But when we understand, we will be grateful for the form that serves as an excellent device to both learn and skillfully teach what the Buddha taught.