Criticism
A good starting point to realize the purpose of philosophy can be this one: taking note that everything can be criticized. There are no statements on which it is not possible to find arguments to validly support the contrary. But criticism is not just demolition; we can think, for example, of the art critic: his work does not consist in saying that every painting is worth nothing because of this or that defect, but, on the contrary, in helping others to realize first of all the merits of a work.
Destructive criticism cannot weaken truth: if something is true, there is no criticism able to destroy it; rather, it guides us to understand the meaning to attribute to the word “truth”. Criticism is a necessary criterion, vital for protecting ourselves from superficiality, illusions, fanaticism; it is not an enemy, it must not frighten us because of its destructive force; rather, it is a tool that, like all other tools, we need to learn to use, otherwise it serves only to do damage.
Among all possible criticisms, philosophers in the past have identified one that at least turns out to be among the most fruitful: it is not possible to prove that life is not a dream. Similarly, we can also observe that it is not possible to prove that while producing an argument our mind has not suffered distractions or deceit, that is, it has not dreamed a little. We can think, for example, of when we wonder about having closed the door, or when we count a large number of objects: if there is the doubt that we could have been distracted (and therefore deluded) during the counting of a thousand card pack, nothing prevents us from thinking that we can have been distracted even in a very short count and, going down to the minimum, also in any thought that appears to our mind as immediate, evident.
Another critical awareness with which we should become familiar is that any reasoning that mediates two elements would in turn require further mediations and so on endlessly. Likewise, each demonstration is based on elements that in turn need to be demonstrated. Finally, we note that any criticism that wants to be really serious and radical must necessarily be able to take into consideration and also face criticism of itself; it needs to be able to do self-criticism as well.