There's an "upvote" button, just to the left of the comment above.

The line between "upvote for good point" and "upvote for agreement" can be blurry, same for downvoting.

In either case, both are accepted uses. PG has said as much:

https://news.ycombinator.com/item?id=117171

Interesting. I guess I was a bit too quick with my previous comment then.

However to me it feels a bit like discouraging alternative opinions, when they are hidden/greyed out.

Is this commonly accepted then?

Honest question: If not for showing agreement, what is the reason for the upvote button?

I thought it meant "nice contribution to the conversation". It's easy to come to this conclusion when you think down-vote means "you're not contributing". I up-voted many comments I totally disagree and down-voted many I agree (because they were unrelated to the discussion). Am I a minority?

Well, the HN guidelines[1] do not mention any rule as what constitutes 'right' voting criteria. As a regular HN user of over 6 years it feels even surreal to be in a discussion about the basic features of this wonderful platform. It's never wrong to question the basic premises of life, though(;

I do believe we have the a similar kind of understanding for when to up-vote. What is a 'nice contribution to the conversation' other than arguments or facts that 'I do agree with' in them being a nice contribution to the conversation.

I fear we would have to have a meta-discussion on the concepts of good and bad and how they are flawed in that there are no montains without valleys^^

1. https://news.ycombinator.com/newsguidelines.html

what's wrong with upvoting with agreement?

Upvoting based on "this comment brings up good points and arguments" rather than "this comment says things that I think are true" helps fight against the community becoming an echo chamber.

We downvote despite "good points and arguments".

The community is in many ways already an echo-chamber; that battle was lost a few years ago. Don't let it bug you.

Isn't "good" just as subjective as "things I think are true"?

The problem isn't subjectivity, it's groupthink. "Good but wrong" posts are better than "bad but correct".

Exactly. It's not that interesting to be in a forum where people are only awarded for being in line with the popular opinion. The alternative is to award constructive contributions.

+1 I agree.