"It is natural that doubt should arise in your minds.
I tell you not to believe merely because it has been handed down by tradition, or because it had been said by some great personage in the past, or because it is commonly believed, or because others have told it to you, or even because I myself have said it.
But whatever you are asked to believe, ask yourself whether it is true in the light of your experience, whether it is in conformity with reason and good principles and whether it is conducive to the highest good and welfare of all beings, and only if it passes this test, should you accept it and act in accordance with it."
- The Buddha
Buddhism is founded on two fundamental observations, from which the rest of the philosophy is derived. These two basic premises are:
(i) The underlying nature of reality is process and change, rather than stable entities.
(ii) Processes can be divided into two categories - mental processes and physical/mechanistic processes (nama and rupa) .
Although mental processes and physical processes interact, mental processes are not reducible to physical processes.
According to Buddhism, the basis of reality consists of ever-changing processes rather than static ‘things’. If any ‘thing’ is analysed in enough depth, and observed over a long enough timescale, it can be seen to be a stage of a dynamic process, rather than a static, stable thing-in-itself.
This becomes obvious when we remember that the universe is itself a process (a continuing expansion from the Big Bang), and so all that it contains are subprocesses of the whole.
The Rationality of Buddhism
Of course most religions don't like having their basic tenets subjected to searching analysis, and Jihadism has abandoned reason altogether, to the extent that you're likely to get your head chopped off for being too rational.
But Buddhism is different. In the Kalama Sutra, Buddha said that all religious teachings, including his own should...
(1) Not be believed on the basis of religious authority, or 'holy' books, or family/tribal tradition, or even coercion and intimidation by the mob.
BUT INSTEAD ONE SHOULD
(2) Test the methodology by personal experience. Does it do what it says on the box?
(3) Is the philosophy rational? Or does it require you to believe six impossible things before breakfast?
(4) Judge the tree by its fruits. Is it beneficial, or does it tell you to act against your conscience and 'The Golden Rule'.
According to Geshe Kelsang Gyatso, Buddha told his disciples time and time again not to accept his teachings out of blind faith, but to test them as thoroughly as they would assay gold. It is only on the basis of valid reasons and personal experience that we should accept the teachings of anyone, including Buddha himself.
Reason versus revelation
One advantage of establishing a rational basis for Buddhism is that it gives Buddhism an 'intellectual respectability' at a time when the intellectual prestige of other religions is in steep decline, due to increasing obscurantism, which takes variety of forms varying from creationist anti-science to outright terrorism.
This 'intellectual respectability' also may help to prevent Buddhism being hit by collateral damage from increasing prejudice against all religions resulting from jihadist aggression.
Most religions contain some 'revealed doctrines' or 'dogmas', which were revealed long ago to one person or a few people, and then not to any others.
In all religions other than Buddhism, these ancient, unprovable, unrepeatable revelations are fundamental articles of faith on which the rest of the belief-system is constructed.
In contrast, Buddhism's fundamental doctrines are accessible to reason and investigation in terms of shared, repeatable, reproducible experience... full article