I wouldn't either, because I value truth as well and I wouldn't give up truth to have happiness. If you are someone who cares about believing the most true things as possible and the least false things, than this would be your personal source of happiness. If you're not, then maybe you would try the machine. — Patulia

I don't think you get my point.

Yes, of course, I take some pleasure in knowing the truth and (accurate) knowledge could be considered a "personal source of happiness".

Still, I have absolutely no doubt I would be way, way happier if I got into the machine (which is devised to maximize my happiness).

But even aware of this fact, I still don't want to get into it at all, because I'm positive that happiness is not "the ultimate purpose of human life", and I'm so deeply convinced about it that I am willing to purposely trade happiness for truth.

Actually, even if hedonism is indeed a coherent philosophy, I really doubt that for most people, "everything we do in our lives has as ultimate purpose to bring us personal happiness".

People often give more importance to some moral and ideological values than their personal happiness, even when these values will most likely not impact their personal happiness. I could give the example of veganism (for someone why adores meat), but you might say people just do it because they personnaly suffer from animal cruelty (which is absurd, because saving a cow out of billions shouldn't really change their mind...)

I have a way better example, and it is a thought experiment. Imagine some scientists offer you to put yourself in a machine, which would guarantee you happiness for the rest of your life (simply by injecting dopamine into you and food so that you don't die). They could even make you hallucinate that you're living in a (very realistic) world they're simulating especially for you, in order to maximize your personal happiness.

Would you get into the machine ? I definitely would not, and I think many people wouldn't eithier, because I value "truth" over happiness.