Common language makes sense when talking about things like knowledge and truth, but if it is inspected, people tend to get uncomfortable, fast.
For instance, it makes sense to ask, “How do you know that’s true?”, and the answer will be along the lines of “Because of x, y, and z.” Ask what knowledge is and you get something like “Knowledge is all of the things we know.”, as if that answers something. Ask about truth and folks mean “the way things are.”
None of that makes sense, however. If knowledge is the collection of everything we know, then truth must be what we know. This makes “How do you know that’s true?” an absurd question. If something is true, it is by definition, something we know, at least in the general sense. The appropriate question then is, “Why do you think that’s the case?” And when one seeks to answer with some, any, explanation, one is justifying a belief. Simple thoughts on “Truth is that which corresponds to reality” are revealed as meaningless, considering it begs the question of “What corresponds?” and how one would know when “correspondence” is reached? For certain, “truth” would be the test for correspondence in that case, which leads right back to a simple fact of justification. Too, if truth is “the way things are”, then substitution works wonders! “The way things are corresponds to reality”; or in other words, reality is reality. When discussing these things, we must be thoughtful and make sense, and common use doesn’t, it turns out to be absurd in most cases.
Finally, when we realize all of the above, it shouldn’t shock anyone hearing that there’s no genuine difference between saying something is true and something is justified.
However, for many, and not just laymen, such a remark unleashes something akin to a swarm of the hornets’ nest, or the frantic sprawl of a fireant colony on three alarms.
After years of interrogating theories of knowledge and looking at our use of these terms, it can only suffice to say that knowledge is all the stuff we think is true, and what’s true are only our ideas about what the case is, and stating what we think the case is, or even believing what the case is, requires justfication, warrant, in every case from belief to doubt to reserving judgment.
Just a thought.