I have always been wondering whether there is a human creature capable of answering all the questions that philosophy as a science asks. And I can never find a positive answer. What I have decided for myself is that the questions of philosophy are the questions of life. As long as life endures, more and more questions appear. If we find answers to them we will be able to answer the question that embraces all these questions: what is philosophy itself? To define philosophy is rather difficult, as like Popkin and Stroll (1993) claim, “philosophy is generally regarded as per­haps the most abstruse and abstract of all subjects, far removed from the affairs of or­dinary life” (IX) and, what is more crucial, “one of the subjects that philosophers have never been able to agree upon is what philoso­phy consists in.” (XI) Does it mean that I should stop finding the answer to the question of what philosophy is? I suppose the answer is no. I see philosophy as a way of thinking, a way of reflecting on the events human life is full of. Popkin and Stroll’s view on philosophy as “a way of dealing with questions, as well as an at­tempt to resolve certain problems” (XI) appeals to me as well. I like the authors’ advice to discover philosophy by studying it and by philosophizing (XV) and I am going to make use of it. One more question that I found particularly interesting in the topic covered is how reliable human sense may be in coming to know the world around us. By simple examples that Russel and Perry’s work (1997) consists of I got to know that what is obvious for one person is absolutely unacceptable by another, that is, the realization of some object through the five senses is rather subjective and cannot be treated as a reliable one by others. Moreover, human senses might be significantly determined by some outside factors and this is another cause not to rely on them when coming to know the world around them. The authors’ claim is that If we take any common object of the sort that is supposed to be known by the senses, what the senses immediately tell is the truth about the object as it is apart from us, but only the truth about certain sense-data which, so far as we can see, depend upon the relations between us and the object. Thus what we directly see and feel is mere ‘appearance’ which we believe to be a sign of some ‘reality’ behind (7). Another issue I found interesting while reading the works is two ways of handling knowledge: either through deduction or through induction. Deductive reasoning is also called synthetic reasoning as it always starts from at least one universal premise. Inductive reasoning starts from abstracting the concepts from sense experience. In the latter case, the connection between abstract concepts and generalizing the relation is established. As far as the problem of a priori knowledge is concerned it was Kant who contributed most to its theory. He has perceived that people have “a priori knowledge which is not purely ‘analytic’, i.e., such that the opposite would be self-contradictory.” (Russel and Perry 1997, p. 58) There exist at least two views on the possibility of knowledge of this type. Kant claimed that a priori knowledge does exist but in spite of its existence “we cannot know anything about the thing in itself or about what is not an act