Buddhism is clearly a massively multifaceted phenomena in the present and one can see, despite claims to timelessness, that it has developed chronologically. To some extent we can trace the development back in time - rather like physicists use the evidence of the present to make conjectures about the early universe. Just as for the universe, the actual origins of Buddhism are obscure and will remain so because we do not have enough evidence and never will have. However we can point to certain features - common to all forms of Buddhism, and emphasised in early texts, which appear to be archaic. One of the main features is the emphasis on practice. Yes, we have considerable amounts of biography, history, sociology and philosophy but the overwhelming concern of Buddhist literature and material culture suggests that what Buddhists did (and of course still do) is carry out certain practices, particularly forms of "meditation". 
I suggest that Buddhist texts are primarily concerned with practice: with the mechanics of practice; with the context for practice; with the fruits of practice. They also contain a technical vocabulary or jargon for understanding and communicating about the process and fruits of practice. Buddhist texts reflect the concerns of Buddhists i.e. a pragmatic program of transformation. The nature of that transformation is the subject of a lot of speculative writing, and one can see changes over time in how it is written about, and we can further speculate about the kinds of socio-political environments the authors lived in and what their religious concerns and ideals were like. But it always comes back to practice.
We are probably familiar with claims from religious believers that their special book contains the absolute truth, a truth which comprehends all other truths and supersedes them. We Buddhists are not immune from this. The claim to truth is very easy to disprove in most cases, which makes religious people look stupid. I once had two Christians come to my door and tell me that all of Newton's laws were found in the Bible. Having recently completed my degree in chemistry (with a sprinkling of physics) I knew Newton's Laws reasonably well, so I asked them in and requested they show me what they meant. They pointed to Genesis 1.14-17 which concerns Jehovah's creation of the sun, moon and stars.  I asked: "how do you get from that to the inverse square law?"  And surprise surprise they didn't in fact know any of Newtons laws. They looked stupid, realised it, and beat a quick retreat. But that was too easy. Newton's laws are irrelevant to their beliefs, and they were foolish to try to explain their faith in those terms. If your faith is not based in science, and you don't understand science, you'd be better off not explaining faith to a scientist in scientific terms.
In this case how should we regard Buddhist texts? It has to be admitted that on the whole the Buddhist texts are badly written, they aren't great works of literature and most people get along fine with summaries and commentaries. Buddhist texts are given to waffle, to tedious repetition, to digression, and to impenetrable idiom. One has to wrestle with hyperbole, superlative, hagiography, idealism, excessive piety, and quite a lot of vicious polemic. In many ways the Buddhist texts appear naive to the modern reader. However no one ever built a statue to a critic,  and all that said there are nuggets and gems within the ore, many of which I have blogged about, that make it all worth while.
I suggest that rather than seeing Buddhist texts as documents of truth, that we should see them as a recipe book or instruction manual. Indeed cooking is one of the metaphors for spiritual practice one finds in the texts. In the texts one finds described a comprehensive pragmatic program which comments not just on how to meditate and what to expect when you do, but how to live a life conducive to meditation, and importantly the value of doing so - both direct and indirect value. It is not simply a philosophy in the contemporary sense, though it is close in spirit to the original sense of philosophy. Nor should we be fooled by the religion that has built up around Buddhism. I don't see the Buddha as a religious man, if anything he was the Richard Dawkins of his day, going around telling religious people not to be so foolish. 
If Buddhism is a pragmatic program, and Buddhist texts are the ancient recipes for this program, then the question "is it true?" becomes irrelevant. With recipes we don't ask if they are true, we ask "does it work?" or even "does it help? Recall that the Buddha's own definition of the Dhamma was anything that helped. [see: What is Buddhism?] And really the only way to find out if a recipe works is to bake the cake and eat it. Much of academic Buddhology and comparative religion is about criticising recipes without doing any baking. Effectively they take recipes as a genre of literature and develop critical theories about this genre. In case this seems an unlikely conclusion I would point out that there are academic articles about recipes, and interestingly one study that I found came to this conclusion:
"The most significant finding of this research is that the evolution of the New Zealand pavlovas occurred largely within domestic kitchens and was the outcome of ongoing and widespread interest in novelty and experimentation." I suspect that if one studied Buddhist 'recipes' one would come to a parallel conclusion - that the recipe books show a gradual evolution over the centuries, with changes driven by practitioners interested in novelty and experimentation (although I would add here that they would also be responding to large scale socio-political events such as the rise and fall of dynasties). The average Buddhist need not pay much attention to literary criticism of recipes qua literature because they are actively putting them into action on a daily basis - proving them in the old sense of that word. One learns more about meditation in a single session of sitting, than in reading the whole canon. Indeed discussions about recipes are only interesting to a certain type of person, even amongst cooks and bakers. The critical approach to the literature does occasionally throw up important or useful results, some of which I have attempted to highlight in this blog. However, I can't help thinking that philosophy is really only a minor consolation, and that perhaps more philosophers ought to take up baking.
- I put meditation in scare quotes because the English word does not precisely match the traditional terms for our practices e.g. bhāvana, yoga, samādhi, dhyana.
- I further note that in Gen 1.14 the "lights of the firmament", as well as being for dividing night and day, seasons and years, were for "signs" - i.e. astrology. Though this passage is often cited as part of an argument that the ancient Hebrews had rejected astrology (associated with the Babylonians) since they give the prosaic name 'lights' to the heavenly bodies, indicating that they did not see the lights as gods or other sorts of celestial 'beings'. Note that the Pāli/Sanskrit word deva literally means 'shining'.
- Newton's law of gravity says that the attractive force between two masses (gravity) is in proportion to product of the masses divided by the square of the distance between them. It is beautifully simple, and accurate enough to land a man on the moon. A summary of Newton's laws of motion can be found here.
- This quote is apparently from the composer Sibelius.
- The Pāli texts record a lot of polemic against religious people, particularly Brahmins and Jains. The Brahmins and Jains for their part were critical of Buddhism as well.
- Leach, Helen. 'What Do Cookery Books Reveal about the Evolution of New Zealand Pavlovas?' http://www.hss.adelaide.edu.au/centrefooddrink/papers/leach.pdf