Pre-Reflection on Theme 1

Bertrand Russell, The Problems of Philosophy (1912), discusses the theory of knowledge, and the fact that knowledge is not as precise and certain as one might think.

"Sense data" and why does Russell introduce this notion

Sense data is introduced by Russell as a way to describe what we know about an object based on how it appears to us; what color it has, how it sounds, and feels if we touch it etc.  The sense data about an object is individual and varies with the observer; it may for instance depend on your angle of view of the object. The sense-data that we are experiencing does not need to express the truth about the object, only how we perceive it and it does not take into account the existence of the object when it is not being observed. The sense-data describes the knowledge we have about an object, and the familiarity with what we are acquainted with associating with the object.  

 Meaning of the terms "proposition" and "statement of fact", and how does propositions and statement of facts differ from other kinds of verbal expressions

Statements of fact, can be true or false, and articulates factual information without argument. This is clarified by Bertrand Russell himself in a lecture "Facts and Propositions" (1918-1919) “Gravitation varies inversely as the square of the distance,” my statement is rendered true by astronomical fact. If I say, “Two and two are four,” it is arithmetical fact that makes my statements true. On the other hand, if I say “Socrates is alive,” or “Gravitation varies directly as the distance,” or “Two and two are five,” the very same facts which made my previous statements true show that these new statements are false”.

Russell (1918-1919) further explains the propositions: “A proposition, one may say, is a sentence in the indicative, a sentence asserting something, not questioning or commanding or wishing. It may also be a sentence of that sort preceded by the word ”that.” For example, “That Socrates is alive,” “That two and two are four,” “That two and two are five,” anything of that sort will be a proposition.”

Both the propositions and statements of fact may or may not be true, just like other verbal expressions, but they are both are precise, deductible and not vague. They also require some kind of acquaintance with the object (regardless if true or false).   

Meaning of the notion "definite description"

Russell discussed that there is knowledge you have from being acquainted to something, and there is knowledge you know by description; like what you know about Julius Ceasar, as you cannot be acquainted with him since he is since long dead. According to Stanford Encyclopedia of Philosophy (revised 2013), you can separate definite and indefinite descriptions by phrases of the form ‘the F’ (definite) and ‘an F’ (indefinite). Definite expressions are referring to the object, whereas indefinite expressions are talking about an quantifiable object. Examples of definite descriptions are on the form “the-so-and-so”, like “the golden mountain”, “the round square” etc.    

Russell (1910-1911): “We have descriptive knowledge of an object. When we know that it is the object having some property or properties with which we are acquainted; that is to say, when we know that the property or properties in question belong to one object and no more, we are said to have knowledge of that one object by description, whether or not we are acquainted with the object.”

Traditional problems in theory of knowledge (epistemology)

How can we know anything at all? How do we know that what we know is true? How can we know that the sun will rise tomorrow, just because it always has in the past?

Russell argues that philosophical knowledge is not different from scientific knowledge, but holds the philosophical main characteristic “criticism of knowledge”. However, the result of that criticism seldom gives reason to claim that man is incapable of possessing the knowledge we have.   

We need to be acquainted with the constituents (=components) in order to understand a statement or proposition, however it is not necessary to be acquainted with its denotation (= explicit or direct meaning of a word or expression). According to Russell (1910-1911) “Every proposition which we can understand must be composed wholly of constituents with which we are acquainted. From what has been said already, it will be plain why I advocate this principle, and how I propose to meet the case of propositions which at first sight contravene it. Let us begin with the reasons for supposing the principle true.”” The chief reason for supposing the principle true is that it seems scarcely possible to believe that we can make a judgment or entertain a supposition without knowing what it is that we are judging or supposing about”.

References:

• Bertrand Russell (1912), The Problems of Philosophy 
• Bertrand Russell (1919) "The Philosophy of Logical Atomism". The Monist (Oct 1918, Jan, April, July 1919); Lectures 1 & 2. "Facts and Propositions" and "Particulars, Predicates and Relations";  available on the The Bertrand Russell Society’s website: http://www.users.drew.edu/~jlenz/brtexts.html
• Bertrand Russell (1910-1911) Knowledge by Acquaintance and Knowledge by Description  Source: Proceedings of the Aristotelian Society, New Series, Vol. 11 (1910 - 1911), pp. 108-128 Published by: Blackwell Publishing . Available on this website: http://wsblog.iash.unibe.ch/wp-content/uploads/Russell.pdf
• Stanford Encyclopeida of Philosophy, http://plato.stanford.edu/entries/descriptions/. First published Tue Mar 2, 2004; substantive revision Tue Jun 25, 2013