Theme 1: Theory of science

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

Russell means that this is our own way to register material things, “matter”. Russell says that it is senses, and as the word means it is exactly that: smell, touch, hearing, sight and taste. In the beginning of the book Russell makes the example of how we see a table, by the way it looks in shape (sight) and that it’s smooth (feel). This is sense-data, all the things we experience from our senses. I believe this can vary from person to person. What I think is smooth, what I think lavender smells like. It should be mentioned that this can differ, but I guess that’s not so important because most examples is based on the sense sight, and we see things the same (“matter”-things at least.)

Russell introduces this notion so that we are clear on that this is something real, our senses are real, but if the table really exists, matter wise, is a different story. So this term is introduced so that we get the picture and understands Russell’s following examples.

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?

From what I can grasp it seems to mean that a “proposition” is like a suggestion you could say. If I would talk about say Henry Ford, I would make a proposition on the basis that I’m only acquainted by history, and then make a suggestion on who he was. That’s how I would translate it anyway, but it’s more complicated than that tough. Statement of fact is somewhat similar, I make a statement about Henry Ford based on the history I know of him, and then this is just fact, but this in turn can also generate my proposition of him. So in my book these things are connected, and have a deeper meaning, and thus differ from other kinds of verbal expressions.

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

First of we look at the notion “ambiguous description” to understand what a definite description is. An ambiguous description is a simple description, like “a car”, this can be any car, somewhere in the world, belonging to anyone, whereas a definite description is, chokingly, a more concrete description. For example: “the car with three wheels” is a more concrete description. This is not an absolute description of course, but this narrows it down much more, and also points to just the one car, thus “the car” instead of “a car”.

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?

In chapter 13 Russell explains that we have 3 different ways to accept, or look at, knowledge.
Russell means that if we believe something to be the way it is, and this is also how it actually is, you are right; this is called knowledge. And the opposite of this, if you believe something that is NOT the way it actually is, you are wrong; this is called error. And the third one is somewhat in the middle of these to. Something that we believe in but it is not knowledge or error (and Russell’s talks about self-evidence: how you judge your own sense-data, and this can of course have different degrees where a high degree is more to be trusted) and in this third way the degree of self-evidence is not the highest, this can be called; probable opinion. And this takes us to Russell’s statement and attack: “Thus the greater part of what would commonly pass as knowledge is more or less probable opinion.”

In chapter 14 Russell points of two things: (1) acquaintance with a thing does not logically involve a knowledge of its relations, and (2) a knowledge of some of its relations does not involve a knowledge of all of its relations nor a knowledge of its 'nature' in the above sense. Where the conclusion Russell makes is the point; in his example a tooth ache. I would know I have it because it hurts and my acquaintance with pain and my teeth are obvious. The relations however, why it hurts and what caused this pain is unclear to me, but not to the dentist, however the dentist can’t feel MY pain and therefore can never be acquainted with any of its patients tooth aches. The point is that both the dentist and the patient only seems to have knowledge of it, the dentist can never really be acquainted to the paints ache and the patient can never really know the relations of the ache, only seem to know them.