In my previous post, I showed that reasoning is different depending on which science the reasoning is about. Since I am specifically interested in philosophical knowledge, it is best to limit ourselves to a discussion of reasoning within philosophy.
As philosophy is the second highest science, it can only take principles from theology. Any time that a philosopher does this he is open to criticism though. Not everyone accepts that theology is an open discipline since some do not believe that God exists or do not believe that he has revealed anything to us. Even if a group of philosophers do agree on these things, they may not agree on what God has revealed. Mormons believe that God has revealed the Book of Mormon, but Muslims think that he has done no such thing. Without discussing theology in detail, there is no way to resolve this problem. Therefore, I will proceed without taking any principles from theology.
When we are reasoning within philosophy there are two problems that we are immediately confronted with. The first problem is the variety of positions. Each philosopher has their own opinion on all of the philosophical questions and they often do not agree with other philosophers. It is rare for two philosophers to agree on anything and no substantive position in philosophy has ever achieved widespread acceptance. The second problem is that no philosopher can agree on what the substantive problems in philosophy are, what philosophers are supposed to study or even how philosophers are supposed to resolve the problems. These problems mean that there are very few agreements on method. I already mentioned them in my last post.
Since my focus is on philosophical knowledge, it might seem that this is a better place to begin. The problem is that no philosopher can agree on what knowledge is, what things are necessary for us to have knowledge or even in which situations we actually do have knowledge. For a while, English speaking philosophers thought that justified true belief was what knowledge is, but that agreement does not exist anymore. But we do think that knowledge is both valuable and something that we have. Investigating these claims may illuminate what philosophical knowledge is.
Skepticism can be investigated by determining why skepticism is plausible and what reasons lead to belief in skepticism. It can also be investigated by determining what knowledge is contrasted with. The claim that knowledge is valuable can also cannot be compared absolutely, because knowledge is intrinsically good. But is knowledge intrinsically good because it is theoretical, it is true or for some other reason? Answering these questions will help to determine what philosophical knowledge is.
Next, I will discuss the plausibility of skepticism by giving reasons to believe in skepticism.