He believes that we shouldn’t focus on what the philosophers are saying, because it is probably wrong, but we should focus on why they are saying it. Although, this could appear to be more to do with Psychology than Philosophy, and so maybe Nietzsche shouldn’t be worrying about it.
Nietzsche believes that philosophers are wrong when they say that truth is the most important thing – for Nietzsche, life is most important. And therefore, if we hold a false belief, that is OK because as long as our lives are better for having this belief, then it is better that we remain ignorant of the truth and stay happy. Too much emphasis has been made of truth.
However, there must be some truths in the world, even if it is very basic without our perceptions. For example, if I see a can on a table, I know that there is one object on top of another object, even if it is only my perception telling me what the objects are?
Plato is a philosopher that Nietzsche heavily disagrees with. Plato said that this life isn't the real one and that when we die, we will go on to a real world that is better than this one. Nietzsche says this is not true. There is not another world or life apart from the one we are living in. Nietzsche believes that there is no truth or real world outside our own perceptions and therefore we should not be talking about another world. Nietzsche is also not a believer in the after-life, unlike Plato and he thinks that Plato is wrong to deliberately not live this life in the hope that the next life will be better. Nietzsche thinks that we only get one life and that we should live it to its full capacity. He criticises Schaupenhauer for not wanting to say yes to life.
But if Nietzsche knows that there is no truth or outside world then he must be sure of this. Therefore, he knows something.
Nietzsche disagrees with Descartes because Descartes believes that we can know one thing for certain – I think therefore I am, and from this we can prove that other things are certain, such as God and the rest of the world. Nietzsche says that this isn't the case and that we cannot know that there is such an ‘I’ – it is not an immediate certainty. There might not be individual thoughts thinking this, but one big collective thought.
But how can I not know I exist when I am thinking? Every individual person has his or her own thoughts which mean that they must exist, otherwise how could they, collectively or individually, be thinking?