The Problems of Philosophy was created in 1912.

Man created philosophy, hence it's flawed.

Philosophy books deal with the topics that philosophy deal with. One of the general themes is how to address the problems in society and the reactions of people.

Philosophy is the study of the fundamental problems to do with knowledge and beliefs. Philosophy is closely related to religion because it's not something that can be proven, It's more to do with opinions.

Philosophy has had an impact on our view on the mind and the world in which we live in.

A section of philosophy dealing with everyday practical problems. For example moral philosophy which deals with a moral dilemma one may find in his own life, is "practical philosophy".