Alternate preconceived conclusion: All three contributed a lot and there's no way to settle the question. That's because I think arguing about which of the three did the most is tiresome.
The very next sentence is, in fact,
And there are whole strings of kindred questions to which you can only get an honest answer from someone who is indifferent to the whole subject involved, and whose opinion on it is probably worthless in any case.
I have found this most wonderful (if fairly lengthy) article, and thought you would enjoy having it brought to your attention.
It is so good, I think we should include it among the references in the "Politics is the Mind Killer" wiki page. But, before that, I submit it to you, and ask you: is there anything in this article that would warrant its exclusion from this site? I mean, besides the fact that it is about politics, and written by a notorious Social-democrat (And is that in itself grounds for exclusion?).