This book gives a great introduction to Philosophy and explains, clear and simple, 101 main terms in Philosophy. This book is an essential book for each person (No matter if is a new or veteran Philosopher), who is interested in Philosophy. Let's take a look at 4 main terms which you can read at this important book:
Ontology – The belief that something exist or not. We can believe that kindness is a virtue which exists within all human beings but, on the other hand, we can say that it is not a real virtue. Moreover we can believe that god exists or not.
Induction - A method that is used in order to conclude wider conclusions rationally from a few observations conducted earlier. In other words, induction is generalization of one incident. The philosophical problem with this kind of method is that you can't always predict the general rules from only one incident. For example: How do we know if there's a unity of what has happened when we made our observations and what will happen if we'll conduct more observations?
Empiricism – A theoretical approach which believes that we can acquire information through our senses: Seeing, touching and so on. Against this theoretical approach we can find Rationalism.
Rationalism - A theoretical approach which believes that we can't acquire reliable information through our senses because they're distorting reality. The better way for acquiring information is by analyzing ideas and the substantive meaning of the world we live in