1. Theory of Science pre-reflection

Bertrand Russell starts his book 'The Problems of Philosophy' by asking a central philosophical question: “Is there any knowledge in the world which is so certain that no reasonable man could doubt it?” (Russell 1919: 1) By doing so, he creates the realization that our assumptions we make in every day live, can be reconsidered by ‘radical doubt’: We cannot be sure that something is even real, although we can perceive it.

Russell explains this by stating that the colour, the shape, the sound and the surface of a ‘table’ always differ according to our point of view. Since we cannot share the exact same point of view, what we see is not the real table, but more of what we infer from our senses. In order to draw the line between our perception of an object and its real existence, Russell introduces the term ‘sense-data’, which he defines as “things that are immediately known in sensation” (Russell 1919: 4).

In our example, the colour, the smell, the sound and the touch of the table are sense-data and their collective experience the ‘sensation’. Because Russell denotes our sense-data to be personal, our sensation may vary and therefore can’t reveal the reality of an object. If there was a real table, which we are unaware of, it would be a ‘physical object’ that can be defined as ‘matter’.

Without having adequate demonstrations, if there is such a thing as matter, Russell states that it must be rational to believe that our sense-data are “signs of the existence of something independent of us and our perceptions” (Russell 1919: 11).

Russell created his concept of sense-data by using Descartes method of ‘radical doubt’ in order to differentiate between appearance and reality. From what I understood, reality might therefore be something that is not immediately present to our sensation.

When he further lays out that knowledge can be gained by acquaintance or by description, he introduces the term “proposition” which is a statement about an object and its relation. Whereas a propositions may be true or can be doubted, a statement of fact can be evaluated as true or false due to its fact and might in some cases be derivative from true propositions (Moore, 1953:  308). Other verbal expressions don’t share the value as being evaluated as true or false by evidence.

According to Russell, “every proposition which we can understand must be composed wholly of constituents with which we are acquainted.“ Russell exemplifies that the proposition ‘a is the so-and-so’, which means that a is something, with which we are acquainted and that only a has the property ‘so-and-so’. When we propose that e.g. ‘Lisbeth Salander’ is ‘the girl with the dragon tattoo’, we would know that only she has the property to be ‘the girl with the dragon tattoo’. Although when descriptions about Lisbeth Salander may vary, the proposition that she is ‘the girl with the dragon tattoo’ would stay the same.

 But even if we are not acquainted with an object with our sense-data, we still could have knowledge about the object because of its description. Russell divides the term description into ambiguous with the form “a so-and-so”, and into definite with the form “the so-and-so”. In our example we could say that ‘a girl with a dragon tattoo’ is ambiguous whereas ‘the girl with the dragon tattoo’ is the definite description. Even though I might be not acquainted with ‘the girl with the dragon tattoo’, I know that she has the given property and I know that there is only one ‘girl with the dragon tattoo’.

Based on Russell’s thoughts, we can say that we know things beyond our own immediate experience (sense-data) through the descriptions of things, i.e. knowledge by description.

In the last chapters, Russell refers to the Platonic dialogue by taking up the question, if we can ever know anything at all?

He tries to come up with a definition for knowledge and has to admit that knowledge is not a ‘precise conception’ and merges into ‘probable opinion’. In the end he states that, “what we firmly believe, if it is true, can be called knowledge” (Russell 199: Chapter 13), when it is intuitive or inferred from intuitive knowledge, which consists of pure ‘empirical’ and pure ‘a priori’ knowledge. When we cannot tell if, what we firmly believe, is true or not – which Russell doubts – it can be called probable opinion and would commonly pass as knowledge, even though it has not the highest degree of self-evidence.

Furthermore Russell criticizes that many philosophers claim to prove fundamental things such as dogmas of religions and the essential rationality of the universe by a priori metaphysical reasoning. In his opinion, these attempts are useless because “knowledge concerning the universe as a whole is not to be obtained by metaphysics” (Russell 1919: Chapter 14). Only methodical doubt, which is according to Russell the essence of philosophy, can reduce the risk of error in knowledge, which will always be susceptible of error since humans are fallible.

References:

Russell, Bertrand (1912): The Problems of Philosophy, Oxford: Oxford University Press.
Moore, G. E. (1953): Some Main Problems of Philosophy, London: Unwin.