What are the prerequisites for knowing something?

Question

I want to get some references, expand and check mi intuitions. I think the epistemological prerequisites to know something are by order:

1. an external reality, which is stable to a minimum degree so knowledge is allowed to trascend the instant and be useful in more situations.
2. a subject with a cognitive system which
   1. does two basic cognitive operations:
      • entities: which are the result of a cognitive operation to segment the reality continuum.
      • classes: which are the result of cognitive operations based on perceived or functional similarities. Are useful to extrapolate previous knowledge to new situations and to provide us behavioural clues for survival.
   2. (external) matches these structured sensations with mental representations.
   3. (internal) establishes relations between entities, classes and entities and classes.

Am I wrong? What more? Can we regard those as epistemological axioms?

Answer 1

Your primitively intuited above "prerequisites" alone are neither necessary nor sufficient as the complete axioms of epistemology assuming epistemology branch of philosophy can be reduced to Hilbert or natural deduction style theories.

Regarding your 1st assumption:

1. an external reality, which is stable to a minimum degree so knowledge is allowed to transcend the instant and be useful in more situations.

What's really necessary is the existence of non-linguistic bearer of truth or falsity formally called propositions. Our ontology may be just brain-in-a-vat or some other simulations via advanced technologies such as those hypothesized by Nick Bostrom. So there may not be external reality as most people naturally posited.

Regarding your 2nd assumption:

2. a subject with a cognitive system .... establishes relations between entities, classes and entities and classes.

What's really necessary is the existence of an agent to establish relations between entities, classes and entities and classes. We can use computer and AI technologies such as expert systems to do epistemology as well. Also here your axiom hasn't provided any specific rules or properties for any of those relations so perhaps it hasn't provided the core technical contents yet...

Analytic philosophers usually treat epistemology as epistemic modal logic, and the real difficulty lies in the intensional features of its truth function rather than classic logic's much simpler extensional features.

Answer 2

There is no prerequisite to knowledge. Either you know, or you don't. I certainly know that I am in pain whenever I am in pain. There is no prerequisite there.

For instance, you propose that there should be an external reality. Well, the notion off external reality assumes that there is an internal reality and one that you know. And, obviously, there is an internal reality and you know it. It is called variously "subjective experience", "consciousness", "the mind" etc. You didn't even thought necessary to articulate prerequisite for knowing that you have a mind, or that you are a mind, or that you know your own mental world.

Second, is it possible to know the external reality you propose there should be? Well, obviously not since you yourself posit it is an assumption that there should be one to begin with, which implies that this is an assumption, not a fact.

Now, replace "knowledge of the external world" with "rational system of beliefs about the external world", and everything falls into place. Rationality here means first that your system of beliefs be consistent with facts, and, second, that your system be logical. What is there that does exactly that? Well, science for a start. Science is our best system of beliefs about the external world. It is consistent with facts, and it is logical. Maybe not all sciences can articulate their system of beliefs quite like physics does, but this is certainly the standard to be emulated.

It baffles me that so many people should be so insistent that we should have a theory of our knowledge of the physical world when it is quite enough to have rational beliefs. You see, the advantage of talking of a rational system of beliefs is that beliefs are revisable. Whenever we come to believe we got it wrong, we update our system. If you pretend you know the world, then whenever you come to think you got it wrong, there is no place to hide. You just have to admit you claimed to know something you didn't.

I believe I have a sandwich in my fridge but is that true? Maybe not but it is still true that I believe I have a sandwich in my fridge. In other words, I know what is my belief.

Can I possibly know that I have a sandwich in my fridge? No since maybe there is no sandwich. Even if I am looking inside my fridge at something furiously looking like a sandwich, it might still be not true that this is a sandwich. So, not I don't know even such a trivial thing as whether or not there is a sandwich in my fridge.

Thinking in terms of beliefs is also immediately more comfortable since you do know what your beliefs are. Beliefs are also gradable from beliefs that are certain to non-beliefs. And, we don't have to change our mind as to whether yesterday we believed we had a sandwich in our fridge even when it turned out there was none.