Both of these concepts are very real and exist. Simply put. The two basic things that would make communism work, are the lack of these two concepts. If one has no awareness of self and no free will, the collective can work and people would be in harmony with the collective. The fact that we have free will and awareness of self works against the collective hive mind because we are aware of our individual wants and needs. You remove these two concepts and the communist is jumping for joy. They stay in the person, and communism will continue to fail.

This self is an illusion. The experience of this is beyond imagination (pun intended). The "self" that experiences this illusion is what I call God. I would call this the greatest truth anyone can experience.

It turns out it's also the most dangerous to misapply.

Post-modernism took this truth and applied it to a realm where it doesn't make any sense. I personally can't wait to see the post-modernist bridge built on the idea that gravity is a euro-centric concept. We must be getting close, I just saw a woman holding up a man's hand in celebration that he won her bike race.

Quantum mechanics seems to defeat pure determinism. However, our behavior can be closely approximated deterministically...or perhaps that is an illusion. Perhaps the mind ,or even consciousness itself, has quantum variables and we have genuine free will.

The fact that you are making these statements means much more than the question itself. What led whoever made this statement to think this way

Thoughts? They talk about what it would mean if everything were mechanistic and why they believe it doesn't work.

The self is an illusion? Whose? Solipsism is paradoxical, self-contradictory, circular reasoning.
As for free will, determinism has some plausible support.

I think about eating a bullet every day...It's my choice to pull the trigger when I'm ready..."and free will does not exist"?..hmmm

I'll give it a stab. I think ones "self" exists based on the fact that you have a unique mind, body, and spirit. This lets you define it. "Free will" exists but in degrees based on an infinite number of variables. For both, however, there is an element of faith.