The problem of philosophy
Philosophy faces a crucial problem, the problem of meaning and doubt. If any statement is merely a (subjective) opinion, then what are we left with? What is the worth in one opinion against another? The only real guideline we have is logic: an argument or theory has to at least be logically sound to be of value. But just because an argument is logical doesn't mean it holds on to absolute truth - the argument merely makes good sense in a hypothetical sense. Philosophy is after all, the quest for absolute truth, is it not? But absolute universal truth can never be reached when one logical opinion is as good as another. If everything is subjective, how can objectivity ever be attained? How will philosophy ever be satisfied? In the end you choose what makes the most sense to you.
We can draw the following analogy:
Opinions are like the leaves of a tree - each leave trying to catch a little bit, or as much of the light from the sun as possible - trying to get to the canopy of truth. Ultimately, there's just one big tree of diverse shades of green, posing as the only absolute: the struggle for the limelight...