True. The "Gettier problem", at least, seems to demand we tack on another condition.

Maybe. At least until we have some handle on Gettier, we should stick to JTB as only necessary conditions.

If you require certainty for justification, Gettier cases cannot manifest themselves. Just throwing that out there.

But that would have the disadvantage of there being no scientific knowledge. That is quite a price to pay.

That's hilarious! As if what we call scientific beliefs, knowledge or whatever, will suddenly make the planes drop from the sky, copper no longer conduct, and so on. It's not really a big deal at all. The only price will be paid in dogma.

But since we do know that Mars is the fourth planet, we do have scientific knowledge.

You're begging the question. If I'm right, we don't know that. It's simply the most likely belief based on current evidence. I think the problem you have with admitting that you don't know Mars is the fourth planet is that you think it means any guess is as good as any other or that we can just make up whatever facts we like. That's not the case, however. It's not black and white, either certain knowledge or complete skepticism. It's not a slippery slope. You just need to learn to live with subtlety.

Truth seekers end up with a belief eventually. Unless they cross over then they know they do not exist.

Truth can only be relative to who you are. When you do not exist . truth shows itself.

I don't understand how you can be certain of a deductive inference. They either stand on premises which have not been demonstrated deductively, or else are circular.

You're begging the question. If I'm right, we don't know that. It's simply the most likely belief based on current evidence. I think the problem you have with admitting that you don't know Mars is the fourth planet is that you think it means any guess is as good as any other or that we can just make up whatever facts we like. That's not the case, however. It's not black and white, either certain knowledge or complete skepticism. It's not a slippery slope. You just need to learn to live with subtlety.

If scientific knowledge is not knowledge, then what is it?

Scientific beliefs. Some beliefs are better tested than others. Quantum mechanics is extremely well tested. String theory is not.

Yes, all of knowledge is belief. But not only belief. After all, some beliefs are not true, but all of knowledge is true. But if there is knowledge, then there must be belief.

I agree. What's your point?

Because when I said there was scientific knowledge, you denied it, and said there was only scientific belief. But that is false.

Alright, so you say it's false. What's your argument or evidence? Why do I have the feeling that your only argument is going to be you acting all flabbergasted and incredulous? "What?! You mean we don't know Mars is..." :sarcastic:

After all, most people know these things. Why don't you?

Your way of philosophizing is odd. You start from a conclusion "most people know these things" and then work backward from there. If I just accept that people know things about the world then what's left to argue about? You're right because you say so.