The gradual unveiling of philosophy

That, therefore, the book been waiting those who profane, though dealing with the philosophy: a gradual shift towards the depths of thought. Clear, concise, without the rigor give way, he introduces, with an original layout at the thought of the great philosophers.
A question, however, why not Bergson and Wittgenstein and Hegel and Spinoza? After all, a philosophical choice that we must not sulk our pleasure!