Theme 1: Theory of science [post 1]

What does Russell mean by "sense data" and why does he introduce this notion?

“Sense-data” is almost exactly what the word sounds like, the data in which we sense. Russell explains it like this:

“Let us give the name of ‘sense-data’ to the things that are immediately known in sensation: such things as colours, sounds, smells, hardnesses, roughnesses, and so on.”

He probably introduces this notion so that he more easily can explain to the readers why we se and interpret different things differently. I can se a valid point in using one name for all the sensations a person can feel because it would else be very confusing to understand , I think. Just take the example with the table, he explained that we all can se a table, but on discovering more things about the table the more we see the table differently. He also uses the term for when he talks about matter and how different philosophers talk about matter differently. Does it exist or does it not?

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 an actual thing, and object that can be either true or false, though can contain doubts while statement of facts try to eliminate that doubt or verify it. So to explain it more clearly proposition is a description of something while statement of fact is almost what is sounds like, its a statement where you take a stand on the fact, is it true or not. When I explain the next question I also mention part of this in that answer.

In chapter 5 ("Knowledge by Acquaintance and Knowledge by Description") Russell introduces the notion "definite description". What does this notion mean?

It means that when we talk about an object we can know it exists. Definite description is when we know something precise about for example an object. Russell explains it by giving an example in form of a sentence. “The man in the iron mask”. Here he says that we know the man and the mask but not who the man is. To be frank I have had a hard time grasping this concept and it took me several times reading it to understand part of it. But in the end, if I understood correctly “definite description” is when we can understand something by simply have it described without having actually experienced it.

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 main points in these two chapters are “Knowledge” and “philosophy” . In chapter 13, Russell discusses whether knowledge is true and if all that is true is knowledge. He thinks that a thing that is true not always need to be knowledge and the other way around. If you got knowledge of ,let’s say someone wrote about someone dying, you can believe that knowledge, but doesn’t mean it is true, to know if it is true you need to actually see it. He also talked about how even if we know something it could actually be wrong, or and error. The last thing mentioned in this chapter is Probable Opinion, which is the thing that is not and error neither knowledge, it is the thing in between. Russell writes:

“…the greater part of what would commonly pass as knowledge is more or less probable opinion”

In chapter 14 Russell talks more about philosophy and different principles. He first talks about Hegel’s philosophy which as Russell explain is indeed hard to understand. Then he continues to talk about philosophy in nature and explained how things and nature and the nature of things correlates to each another. Russell wrote:

“…acquaintance with a thing does not logically involve a knowledge of its relations and a knowledge of some of its relations does not involve a knowledge of all of its relations nor a knowledge of its ‘nature’…”

He goes on by saying that the things Hegel believe, that the universe is a single harmonious system cannot be proven when we look at nature of things. He continues with space and time and how different principles explains it in different ways. He ends this chapter to talk again about errors and risk and how some risks are to small and can be negligible.

Reference:

Bertrand R, The problems of philosophy (1912) Oxford - Oxford University Press (Republished as ebook-2009).