In the very first philosophy classess one of the major topics taught is Epistemology.Which focuses on questions like "What is knowledge?", "How is knowledge acquired?", and "What do people know?".
This is a very important subject because people shape their lives and world views on their epistemology.Some people have suggested that inorder to choose between world views eg to choose between determinism and free will,atheism and theism,you have to have a certain epistemology or theory of knowledge(which is free from any metaphysical prejudices) and then apply it to the facts of experience or nature and then decide what reality is all about.
It may seem reasonable to say that we should ask ourselves how we know what we know,and then proceed to compare with what we know,so as to get a grip on what is reality/factual.
One of the respected Christian Theologian the late Greg Banhsen showed that its impossible to develop an epistemology without already presupposing something about reality.
An example he gave is:
Imagine you have an Apple farm.Inorder for you to sell your apples you will need to sort the good apples from the bad apples..So you decide to develop the first ever Apple sorting machine.
This machine will sort the good apples from the bad apples.This machine is a method of apple sorting.
The big question is,would you be able to develop such a machine if you did not know in advance a good apple from a bad apple?
The answer is obviously no.You need some prior knowledge of good apples from bad apples.
The same applies to almost all metaphysical questions.If you do not know something about reality,then you cannot devise a method which "sorts"truth and false about reality.Therefore you cannot even devise an epistemology.
Banhsen shows that everyone begins with a worldview and conception of reality.So neutrality is illusionary.
Philosophical methodism,which is the view that method takes precedence over every other consideration in philosophy.
One first gets a method of "knowing" then you argue about ethics and metaphysics.The apple sorting machine shows the impossibility of philosophical methodism.
Watch Banhsen's full lecture here.Very interesting.