I think that one of the most profound philosophical ideas to come out of the work is the simple question of what constitutes reality. There is an objective reality, but how does that actually constitute it when another person does not accept it? Willy is in his own reality and it seems quite real to him. The conversations with his dead brother, the flashbacks, and the schemes in his own mind that constitute success are all elements that are not shared by others. Yet, they are real elements to him. They have validity as reality in accordance to his own mind. I think that it is here where there is a very interesting philosophical examination as to the nature of reality.
I think that another philosophical issue present in the drama is how to accept the futility of freedom. Philosophers have discussed the importance of freedom and how the use of freedom carries with it a sense of the intrinsic value or worth, regardless of consequences. Willy challenges this in that he believes that freedom has to result in success, in what he defines as success. Outside of that, he argues that freedom has no purpose. While this might be rebuked by philosophers, Willy is not alone and in this, an examination of freedom happens. How does one reconcile the use of freedom with the lack of a guarantee of its results? It is here where challenge presents itself and it is here where I think that another philosophical issue raises itself in the course of the drama.