I'd never heard of him. Stanford has this to say...
https://plato.stanford.edu/entries/hare/#Aft

His philosophy is currently somewhat out of fashion, in part through a reversion to various forms of cognitivism in ethics, in part through changes in the style of philosophy, which now pursues the clarity that he desired through a new complexity and professionalization. At least in the short term, it is probable, and in accord with the “strange dream” from which we started, that his thinking will come to be viewed from a distance, as playing a once important role within the non-cognitivist strain in ethics that was dominant through much of the 20th century. And yet it may yet come to hold the attention of a new audience through its recognition of the tensions inherent in any practical thinking that responds without complacency to the aspirations of our ethical ideals, and the limitations of our moral capacities

Here's the strange dream, just to make that reference clearer...

I had a strange dream, or half-waking vision, not long ago. I found myself at the top of a mountain in the mist, feeling very pleased with myself, not just for having climbed the mountain, but for having achieved my life’s ambition, to find a way of answering moral questions rationally. But as I was preening myself on this achievement, the mist began to clear, and I saw that I was surrounded on the mountain top by the graves of all those other philosophers, great and small, who had had the same ambition, and thought they had achieved it. And I have come to see, reflecting on my dream, that, ever since, the hard-working philosophical worms had been nibbling away at their systems and showing that the achievement was an illusion. (2002: 269)

.

When you remember his work, what is it that you consider significant?

I read the Stanford article earlier today. It seemed to me to quickly descend into the nitty gritty rather than give an overview.

The rejection of Ayer's emotivism was memorable, and the systematic analysis of prescriptive language. Speaking roughly, he derived the categorical imperative from considerations of the language of morals, a curiosity.

I suspect there are other less stringent – rigorous – forms of non-cognitivism for those inclined to it which probably accounts for the general neglect of Hare. I'm in the cognitivist camp (perhaps a vestige of Catholicism I couldn't exorcise back in the day) and only vaguely recall reading some of his work back in the '80s before moving on to other Oxbridge thinkers.

I've never heard of him, but then I never heard of Wittgenstein or Austin until I visited these forums. I think I'll see where this rabbit (Hare?) hole leads to.

What I know about him was I had an instructor who was working on his Ph.D. at the time and he mentioned his research related to Hare. This is the anthology he eventually published, which I never read, but I remembered having seen it later. https://www.abebooks.com/Hare-Critics-Essays-Moral-Thinking-Seanor/31274325994/bd

Thanks for the trip down memory lane. More Googling located the author, now a high school teacher at a local private school.

Who's even heard of him? — Banno

I have never heard about him either, but that's one of the main causes of this forum: to learn something new everyday. So, I did a research on what was the papers of R.M. Hare and I found interesting information: https://encyclopaedia.herdereditorial.com/wiki/Prescriptivismo

To analyze moral statements, Hare distinguishes the phrastic part and the neustic part. The first (phrastikon, from the Greek "to point") reflects the content of the statement, or what someone says; the second (neustikon, from the Greek "to nod one'), the position that the speaker advocates before said content, or the use he makes of the meaning of the statement. Thus, for example, "thou shalt not kill" can be broken down into his fastical, "men do not kill their fellowmen," and in his neustic, "and this is the conduct which I earnestly exhort you to put into practice."

May I recommend Hare’s successors, Horgan and Timmons, the only other people to ever get metaethics correct, in their nondescriptivist cognitivism. (It’s basically the same as the metaethics I independently invented before I discovered them; and prior to discovering them I thought Hare was the closest to correct out there yet).

I can say I've read him, but that has more to do with my eclectic way of gathering anything I can find that's related to what I'm thinking through (in this case the starting thread was deontology and Kant, IIRC)

My memory was I didn't really like it -- you mentioning moral certitude rings true to memory, but what we are respectively certain about made it hard to like.

What rendered him so very unfashionable? Who's even heard of him? — Banno

I participated in a philosophy zoom meetup discussing the youtube conversation between Hare and Bryan Mcgee a few months ago. The consensus of the group was that Hare was too universalistic about moral judgement.

, , , , , thanks for the comments.

Only sees merit in his approach, it seems. Horgan and Timmons don't seem very appetising, after brief research.

I remain incline towards the view that moral statements have a truth value, contra Hare, and so to reject his idea that they ought be parsed as an imperative. But I might dig out Language of Morals in order to review his argument there to that end.

The thing that I like about Horgan and Timmons is that they salvage a lot of of what I think Hare has of value to offer, but also retain cognitivism and grant moral statements truth-values. Their initial work was in establishing that cognitivism doesn't have to entail descriptivism, so you can have propositions that do things other than say that the world is such-and-such way -- notably, they can instead say only that the world ought to be such-and-such-way -- and nevertheless be truth apt in the sense needed for objectivity and rationality (though not in a narrower sense of "truth" that bakes in descriptivity).