Theme 1:theory of science - prior

In the book The problems of philosophy, the author Bertrand Russell talks about sense-data. That is the things that are immediately known in sensation, such as colours, sounds, smells, etc. For example if we are to know anything about an object, like a table as Russel describes, it must be by means of the sense-data which we associate with the table. This can be the brown colour, oblong shape, smoothness etc. According to Russell we cannot say that the table is the sense-data or even that the sense-data are directly properties of the table. The sense-data depends upon the relations between us and the object.

Russell introduces this notion of sense-data to help in considering if objects such as a table really exist and if so what sort of object it can be.

A proposition is a declarative statement which asserts some matter of fact. These assertions have a truth-value, meaning they can be either true or false. This makes them the primary bearers of truth and falsity. Statement of fact can also be true or false depending on if the fact corresponding to the statement is true or false. The common denominator between propositions and statements of fact is that they have a truth-value and that separates them from other kinds of verbal expressions like for example opinions.

When talking about knowledge by description, Russell separates two different types of descriptions, “ambiguous” and “definite”. A description can be of the form “a so-and-so” or “the so-and-so” where the first one is ambiguous and the second definite. Such a description of an object as a definite one means that there is one object, and no more, having a certain property. An example of such a description is “the man with the iron mask”.

Russell is reasoning around if knowledge could be defined as “true belief”. At first sight it might seem so but according to Russell it is not. He goes on to say that a true belief cannot be called knowledge when it is deduced by a fallacious process of reasoning, even if the premises from which it is deduced are true. 

Further on Russell discusses the hope of finding reasons to believe that such things as the fundamental dogmas of religion can be proved by a priori metaphysical reasoning. This view turns upon the “nature” of things which means “all the truths about the thing”. The author reasons that if that’s the case then we cannot know a thing’s nature unless we know all the things relations to all other things in the universe. Russell concludes though that “(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”. He goes on to draw upon an example of his toothache which although he has the best knowledge by acquaintance there is, he does not know what the dentist can tell about the cause of it and therefore does not know the nature of the toothache.