The Sense of a Proposition is the Means of Verification
This post is also available in: English (Engels)
This article contains a criticism of logical empiricism. Logical Empiricism has been shaping our thinking in the past century, with influential thinkers like Bertrand Russel and A.N. Whitehead. Usually we are not aware of these influences in a naive assumption that thinking is an objectively validated activity by itself, which of course it isn’t. For activities like business modelling it is imperative to dive into the philosophy of thinking. Why? Because our models will be fundamentally flawed if we do not.
The title of this article is a statement that is regarded as the essence of logical positivism, or a foundation of a Theory of Meaning. I was reading a book on Wittgenstein  when I encountered the following paragraph, which struck me as particularly relevant for us poor business modellers who are endowed with the responsibility to model complex domains because we are forced to do so in order to build a software system that actually supports the business instead of hindering it. The paragraph is reported from a meeting between Wittgenstein and Schlick and Weismann, two of the proponents of logical positivism around 1930.
If I say, for example, ”Up there on the cupboard there is a book”, how do I set about verifying it? Is it sufficient if I glance at it, or if I look at it from different sides, or if I take it into my hands, touch it, open it, turn over its leaves, and so forth? There are two conceptions here. One of them says that however I set about it, I shall never be able to verify the proposition completely. A proposition always keeps a back-door open, as it were. Whatever we do, we are never sure that we are not mistaken.
The other conception, the one I want to hold, says, ”No, if I can never verify the sense of a proposition completely, then I cannot have meant anything by the proposition either. Then the proposition signifies nothing whatsoever.”
In order to determine the sense of a proposition, I should have to know a very specific procedure for when to count the proposition as verified.
What did I read in this paragraph?
First I think it may be relevant in this context to tell that Wittgenstein in this period of his life started to deviate seriously from the theory that he exposed in his Tractatus. He has been cited often for his disdain of what he called “chatter”: senseless talk without any real content or meaning. Talk can have meaning, but usually this is not the case, and in an extreme form he is known to have stated that the essence of a lifetime of achievement can be expressed in only one sentence. The rest is, as said: “chatter”.
But we are talking about meaning here, and a revealing conviction that no meaning can be hidden in statements that “leave a back-door open”. To me this is very rigid, one-dimensional thinking. It feels like Cartesian thinking, or Euclid’s Geometric axioms. Even though Wittgenstein in this period of his life already seriously moved away from Bertrand Russel, the idea that it must be possible to reduce meaning to its essence is still prevalent. At least to me, and I am hoping that readers will comment. It seems to me that Wittgenstein, and others employing this dialectic, is completely incapable of being aware of context. It reveals a mental model of the world that hacks the world into separate and disjoint components, the same mental process that was the origin of the scientific method of reductio that cut-up objects to “reveal” how they worked and what they were made of, but in the process destroyed what made these objects what they were: entities interwoven with their environment.
A statement (or a modelling construct for that matter) is never isolated and has no meaning on its own. It is the context that determines meaning, as far as there is one. Meaning is not isolated, a proposition can never be shown to have meaning in itself. For the book location statement, the only meaning that can be allocated to the statement, is that someone wants to read the book or get hold of it for some reason. In that context, the statement has meaning: the person is helped to find the book. Even that (and I mention this in the context of domain modelling because a trap the modeller can walk into is smugness of completeness) can often be not enough. The question should at least be asked why the asker wants to get to the book. We should continuously try to get as close to the original or authentic goal, and reason from there (Time Inversion Pattern) on the various ways to get there.
To summarise: a proposition has a continuous “meaning”, the value of which increases in growing models.