That’s an attempt to dismiss epistemic rationality by arguing that only instrumental rationality matters.
No. Please note that the terminology here is overloaded, hence it can cause confusion.
Instrumentalism, in the contex of epistemology, does not refer to instrumental rationality. It is the position that concepts are meaningful only up to the extent that they are useful to explain and predict experiences.
In the instrumentalist framework, you start with an input of sensorial experiences and possibly an output of actions (you may even consider your long-term memories as a type of sensorial experiences). You notice that your experiences show some regularities: they are correlated with each others and with your actions. Thus, put forward, test, and falsify hypotheses in order to build a model that explains these regularities and helps you to predict your next experience.
In this framework, the notion that there are entities external to yourself is just a scientific hypothesis, not an assumption.
Epistemological realism, on the other hand, assumes a priori that there are external entities which cause your experiences, they are called “Reality” or “the Truth” or “Nature” or “the Territory”.
Believing that abstract concepts, such as mathematical axioms and theorems, are also external entities, is called Platonism. That’s for instance, the position of Roger Penrose and, IIUC, Eliezer Yudkowsky.
The distinction between assuming a priori that there is an external world and merely hypothesizing it may appear of little importance, and indeed for most part it is possible to do science in both frameworks. However, the difference shows up in intricate issues which are far removed from intuition, such as the interpretaion of quantum mechanics:
Does the wavefunction exist?
For an instrumentalist, the wavefunction exists in the same sense that the ground beneath their feet exists: they are both hypothesis useful to predict sensorial experiences.
For a realist, instead, it makes sense to ponder whether the wavefunction is just in the map or also in the territory.
No. Please note that the terminology here is overloaded, hence it can cause confusion.
Instrumentalism, in the contex of epistemology, does not refer to instrumental rationality. It is the position that concepts are meaningful only up to the extent that they are useful to explain and predict experiences.
In the instrumentalist framework, you start with an input of sensorial experiences and possibly an output of actions (you may even consider your long-term memories as a type of sensorial experiences). You notice that your experiences show some regularities: they are correlated with each others and with your actions. Thus, put forward, test, and falsify hypotheses in order to build a model that explains these regularities and helps you to predict your next experience.
In this framework, the notion that there are entities external to yourself is just a scientific hypothesis, not an assumption.
Epistemological realism, on the other hand, assumes a priori that there are external entities which cause your experiences, they are called “Reality” or “the Truth” or “Nature” or “the Territory”.
Believing that abstract concepts, such as mathematical axioms and theorems, are also external entities, is called Platonism. That’s for instance, the position of Roger Penrose and, IIUC, Eliezer Yudkowsky.
The distinction between assuming a priori that there is an external world and merely hypothesizing it may appear of little importance, and indeed for most part it is possible to do science in both frameworks. However, the difference shows up in intricate issues which are far removed from intuition, such as the interpretaion of quantum mechanics:
Does the wavefunction exist? For an instrumentalist, the wavefunction exists in the same sense that the ground beneath their feet exists: they are both hypothesis useful to predict sensorial experiences. For a realist, instead, it makes sense to ponder whether the wavefunction is just in the map or also in the territory.