As with many things, I come across a view/claim that I cannot resolve or that I don't completely buy.

The claim is this:

Absolute certainty is possible only via phenomenological sense-perception in any present moment (that is, sense-perception not separated by time). For example, "I am aware that some experience is occurring as I type this," or "I sense things in this moment".*

Do you disagree? — numberjohnny5

Yes and no. I agree with (the spirit of) Kierkegaard that the only thing we really know is what it feels like to be alive. But that is a poetic attack on grand intellectual philosophical projects.. not on the possibility of knowing that there's a table in the next room.

Could you give context for the view you're talking about?

Hi Mongrel.

First, I want to clarify what I mean by "know" or "knowledge", just so that we're on the same page. I'm using the common philosophical definition (at least in analytic circles) of knowledge as justified, true belief. So knowledge is a type of or subset of belief. I also think that those constituent parts of knowledge (i.e. justification, truth, and belief) are subjective and thus relative. Moreover, justification refers to a method of reasoning for a belief (like empiricism or logic); truth refers to the correspondence theory of truth; and belief refers to "confidences" in something.

Now, usually I don't think we need to be certain of what we're claiming with regards to knowledge to be able to call it "knowledge"; that is, we don't need 100% (or absolute) certainty on any knowledge claim when saying, for example, "I know my name" or "I know I'm not a brain in a vat" or "I know we're not in the matrix and this is some simulation of reality" or "my car is parked outside". So in this sense, certainty with regards to knowledge is a red herring. I can be maximally certain (that is, up to 99.99% certain) of knowledge claims, but never 100%.


So with that in mind, I'm trying to determine whether we have any 100% knowledge of anything in reality. My view is that we can but only within a phenomenological-in-the-moment-sense-experience-of-something, and not with anything in which time separates the "presentness" of experience.

First, I want to clarify what I mean by "know" or "knowledge", just so that we're on the same page. I'm using the common philosophical definition (at least in analytic circles) of knowledge as justified, true belief. — numberjohnny5

That would be knowledge-internalism. The opposing view is knowledge-externalism. Both views have strengths and weaknesses.

; truth refers to the correspondence theory of truth; — numberjohnny5

That theory benefits from being pretty intuitive. It's foundations may be shaky, though.

My view is that we can but only within a phenomenological-in-the-moment-sense-experience-of-something, and not with anything in which time separates the "presentness" of experience. — numberjohnny5

What belief would be justified by sensory experience? Give me an example.

What belief would be justified by sensory experience? Give me an example. — Mongrel

Sure. As I mentioned in my initial post: "I am aware [or believe] that some experience is occurring as I type this," or "I sense [or believe] things in this moment".

That would be knowledge-internalism. The opposing view is knowledge-externalism. Both views have strengths and weaknesses. — Mongrel

To be honest, I haven't read much about the Internalism-Externalism debate, but the reason I probably side with the Internalism side is that since beliefs are mental and knowledge is a subset of belief, then knowledge is mental (along with its constituent parts, of course).

"I sense [or believe] things in this moment". — numberjohnny5

I'd say there's a sense of that statement that is indubitable.

o be honest, I haven't read much about the Internalism-Externalism debate, but the reason I probably side with the Internalism side is that since beliefs are mental and knowledge is a subset of belief, then knowledge is mental (along with its constituent parts, of course). — numberjohnny5

And that outlook sets the stage for mind-body conundrums. Externalism is explicitly an attempt to fly free of those issues. There's a good SEP article about it: http://plato.stanford.edu/entries/justep-intext/. I found it to be a can of worms... the questions just keep rolling.

Also.. what do you think of Wilfrid Sellars?

And that outlook sets the stage for mind-body conundrums. Externalism is explicitly an attempt to fly free of those issues. There's a good SEP article about it: http://plato.stanford.edu/entries/justep-intext/ . I found it to be a can of worms... the questions just keep rolling.

Thanks for the link. I've read more on semantic internalism/externalism than epistemic so this is helpful. I'll need to digest the subject-area more, but at a glance, it seems that one is necessarily dependent on or influenced by external factors (a la externalism) for all aspects of knowing or perceiving; that seems like a given or truism. However, I think that the mode or kind of justification one adopts for knowledge is necessarily subjective and is also necessarily mentally organised/constructed, which convinces me that internalism or possibly mentalism makes more sense.


I have never heard of Sellars. I'll give him a read and hope to get back to you.

Absolute certainty is impossible. I'm absolutely certain of it!

I see what you did there!

But can one argue out of this contradiction if they believe the first claim to be true?