For me, the essential conundrum of rationalism is that the larger structure in which rationality must be placed can be misunderstood. I'l try make that clear with a religious example.

In the monotheistic thought, people can end up thinking that God has just one eye -- is a Cyclops.

It is not that they actually believe that their God is a Cyclops but they are accepting that God is based on a 1 of divine stature and then they take the idea too far.

The hard part is therefore when to stop seeing God as the singular and overall one when looking at the very refined detailed levels. The more refined the unifying details of our thinking, the more God will turn out to be a Cyclops without our being aware of that.

Rational thought is fine. But we have to accept that we were created in the image of God (so God has two eyes for sure) and not make God be the creation of our own rational imagination. We have to draw the line in the sand for ourselves. God is not going to do that for us.