To question the objectivity of our understanding of the world is not to doubt objective reality. It's a very straight-forward concept, that what we perceive isn't necessarily accurate. We understand that there are optical illusions, and that cavemen didn't know what the moon was.
The more we see, the more aware we become of exactly how our perceptions mislead us. It's unintuitive to accept that this means we are still being mislead. Has science figured everything out, yet? Of course not. This is not at all to knock science. What makes it great is the way it never concludes. Science is always an open question, looking to be proven wrong. It's by being proven wrong that progress is made. As Feynman put it, science is never proven right.
This isn't just about science and human knowledge in the broad all-encompassing sense. This is also about what we think we're doing exactly, as individuals, as we stumble through our daily lives. What we know, what we understand, and how accurate it all is can have a whole lot to do with that, but further, more accuracy isn't necessarily beneficial. We are evolved to be effective, not accurate.
Causality is fundamental to everything, and yet, explanations are often called excuses. Wanting to understand the how and why, a futile exercise. Decide, judge, act. Just do. Don't waste time trying to make sense of it, when you can charge full throttle ahead, and hope for the best - and in many situations, that is what actually works best. What is that but confidence? Even inflated by ignorance and irrationality, it tends to be much more Darwinistically beneficial than reticence.
It's a trade-off though. It's a pretty straight line to point out how this means being wrong about all sorts of things. Science might always be an open question, never entirely right, per se.. but it gets a lot closer than those who don't even try to sort it all out. Does it really matter? Not necessarily. Unless you care about being right. Rational, accurate, honest. Evolution just wants you to have lots of kids.
Evolution doesn't really want anything, I know - but neither do you. What we are and what we think we want, it's all just a product of causal relations, just as evolution is. We personalize it because that's one of the many ways our minds have evolved to mislead us. The illusion of ego leads us to think we make things happen. We define who we are. We are confident or we are lazy, we exist and we need to make better choices.
Better choices will sometimes be made. Sometimes not. There will be reasons. An elaborate causality to it, in which the conceptual insertion of personal responsibility is unnecessary. "je n'ai pas eu besoin de cette hypothèse."