After my spur of research in the Motivation litterature in 2015, i've gradually drifted toward spirituality. This is because it now seems to me that the most persistent illusion that seems to cause the most havoc is the sense of self or "ego." Our ego is constantly out go get something out of fear or desire, motivations driven by more ancient parts of our brain, which then twist our higher intellect into its service.
Having tried some psychedelics it sometimes happens that people get glimpses of the ego-less state, but then most people quickly fall down again once the effect of the drug wears out. Scientifically the drug pushes activation away from the so-called "default-mode network" which is associated with sense of self and ruminating thoughts revolving around that self. Removed from that DMN, an energy-draining black hole, the activation spreads to the higher cognitive functions of the outer brain and reality is seen without the filter of our ego, our personal lawyer that confabulates all kinds of things to fit a personal narrative and bias.
Some of the spiritual traditions have been warning about the ego, and ego-ism, in this sense, that the DMN gets too much energy and can spiral into destructive, internal loops and depression. However aside from catching glimpses of a state with no ego and ruminating thoughts, the only real way to fight it is to fully understand how it works, and not just intellectually, but using our own awareness to catch the ego in action.
This is called the "direct path" in buddhism, and it goes by way of asking "Who am I?" and being aware as consciousness turns inwardly; one can also ask similar questions, such as "What is here?" or "Where does each thought come from? Where does it go?" or "What feels the feelings?" and other such meditative questions that if we pursue diligently with awareness, honestly and truthfully, we can gradually begin to understand how the mechanisms of defense, fear, jealousy, and embarrassment work in ourselves.
The more we look within to be aware of these things directly from our own experience, we can see how thoughts come, where they come from and perhaps some of the underlying motivations for those thoughts. Then rationality really becomes a matter of deep understanding instead of arguments coming out of nowhere to justify an illusory ego that binds to a given idea or cause out of fear for lack of identity or desire to be something.