The basis of buddhism is indeed meant to be four noble truths so I don't understand what you mean.
It's true that Buddhism has the four noble truths. At the same time, it can be said that the basis of Buddhism is that nothing is solid and that everything changes, and that when the four noble truths or the noble eightfold path or the three characteristics of human existence or the twenty-seven whatevers turn into dogma and become rules, that's a problem.
"Our mind is always seeking zones of safety. We're in this zone of safety and that's what we consider life, getting it all together, security. Death is losing that…The mind is always seeking zones of safety, and these zones of safety are continually falling apart. Then we scramble to get another zone of safety back together again. We spend all our energy and waste our lives trying to recreate these zones of safety, which are always falling apart. That's the essence of samsara -- the cycle of suffering that comes from continuing to seek happiness in the wrong places."
- Pema Chodron, Comfortable with Uncertainty, p. 23