There are some people who deny man to be able to know the truth
The skeptic is that who affirms knowledge to be true for someone and false for another one. So, he concludes that anything can be affirmed or denied with certainty, that all is pure opinion and it is only right neither to affirm nor deny anything.
The skeptic believes that men defend the most different positions about any question, and all of them believe to be right.
Others draw on some verses of the poet Campoamor which say: “Nothing is true or wrong: everything is like the colour of the glass you see through”. Replaying to this the philosopher Ortega y Gasset defends that two men can gaze at the same landscape, but they do not see the same, because of their different culture, concept of beauty and tastes and hobbies. Could some of them affirm the landscape of the other to be false? Obviously not. But it would be also not reasonable if both judged as illusory the described landscapes.
JOHN: It seems to me radical enough to say that the truth cannot be known.
MARY: I think to be difficult to know completely the truth, but we can bring it closer.
JOHN: The truth can be known from several points of view.
MARY: I agree with you about that: everyone sees it from their culture, tastes and their way of thinking.