truth, realism, antirealism

So a method of philosophy is to giving necessary, and sufficient conditions for terms. We abbrivate it by "iff". One example of this is:


S knows p iff 1. S believes in p, 2. S is justified in p, and 3. p is true.

Notice that condition 1, and 2 focus mainly on the agent S. It deals with issues that are intrinsic to S. It is concerned with the intention, and attitude of S. Condition 3 is different from condition 1, and 2 in that it does not concern itself with the intention, and attitude of S. Condition 3 assumes that p has a true value( ie: true, false), and that something makes p true. What actually makes p true? Let` s look at it. Suppose p is "The moon is made of cheese". p has a definition truth value, so p could be either true, or false. You might claim that p is obviously falses, but why? You might reply with the reason that you could see the moon is clearly not made of cheese with the aid of some telescope. So, to make this intuition clear. You are saying we can determine the truth value of p by looking. Here is another problem. How do we know p is true if we can` t see anything. For example, we never see quarks, so how do we know they exist? How do know the number of quarks in an atom if we can` t see the quarks in the atom? How do we know the truth value of the proposition " There are 3 quarks in a proton"? These are important questions. The question of what makes p true is a important question in the theory of truth. The question of how we know the number of quarks in a proton is an important question in the debate on observables between scientific realism, and antirealism.

Reply to the two questions i mentioned above.