1. What does Russell mean by "sense data" and why does he introduce this notion?
Sense-data is a notion Russell introduces and defines as the things that are experienced by our senses. For example colours, sounds, smells, hardnesses and roughnesses.
The notion is introduced by Russell to help us clarify the definition of objects, because everyone experiences things differently with their senses, the sensations we obtain differ depending on person.
What the senses immediately tell us about an object is not the truth about the object as it is apart from us; it is only the truth about certain sense-data, which depend upon the relations between us and the object.
2. What is the meaning of the terms "proposition" and "statement of fact"? How does propositions and statement of facts differ from other kinds of verbal expressions?
Proposition is something that is described and known to be true, but we can´t know for sure. The statement “it is true that x” is true if the proposition “that x” has been considered as true. A proposition is when we know certain things, but we are not acquainted to this thing personally and we don’t know exactly what it is. But according to Russell only because the proposition “two plus two equals four” is considered true does not a similar (mathematical) statement have to be true.
When there are many evidences supporting a proposition it can turn into being considered as a statement of fact. Every statement of fact is in based on propositions that have been proven to be true.
3. In chapter 5 ("Knowledge by Acquaintance and Knowledge by Description") Russell introduces the notion "definite description". What does this notion mean?
The notion ”definite description” is defined by Russell as the specific description of something: any phrase of the form 'the so-and-so' in the singular. A different description that is introduced by Russell is the ambiguous description, which is of the form ”a so-and-so”.
For example “the woman with the mask” is a definite description, the phrase ”a woman” is a very ambiguous description and could mean any woman and cause confusion.
4. In chapter 13 ("Knowledge, Error and Probable Opinion") and in chapter 14 ("The Limits of Philosophical Knowledge") Russell attacks traditional problems in theory of knowledge (epistemology). What are the main points in Russell's presentation?
The theory of knowledge (epistemology) is about what knowledge is, which often is defined as “true belief”. Russell states that the definition implies that everything we believe and turns out to be true is a achieved knowledge from what we believe. But this is not correct, because for instance if I believe that a friend of a friend’s name began with an S and she turned out to be named Sarah, my belief was true. If I instead believed that the girl’s name was Sophie, I still would believe that her name would begin with an S, but even though this belief turned out to be true it’s not to be considered as knowledge. Therefore the definition of knowledge is problematic, according to Russell; “a truth is not knowledge when it is deduced from a false belief”.
Another problem with knowledge that Russell discusses in the text is about other philosophers belief to prove things like fundamental dogmas of religion, rationality of the universe, delusiveness of matter by a priori metaphysical reasoning. Russell argues that such theories are not valuable because metaphysics are not able obtain all the knowledge about everything.
Great examples in your answer, it made it easy to understand what you meant. And you summarized the most important from the text, good work!
SvaraRaderaI feel I got the same understanding as you when reading your blogpost. Maybe you could add something about the knowledge by definite description being a way to construct an understanding of something you haven't experience through sense data. I like the examples you provide since I get the feeling you as well as me got tired of only reading examples that only included men :)
SvaraRadera