Logic is an awesome tool that took us from Greek philosophers to the gates on our computers. The challenge with pure rationalism is checking the first principles that the thinking comes from. Logic can lead you astray if the principles are wrong, or you miss the complexity along the way. On the missing first principles, look at Aristotle. One of the history's greatest logicians came to many false conclusions. On miss…
In the most ideal circumstances, these are the same. Logic has been decomposed into model theory (the study of what is true) and proof theory (the study of what is provable). So much of modern day rationalism is unmoored proof theory. Many of them would do well to read Kant's "The Critique of Pure Reason."
Unfortunately, in the very complex systems we often deal with, what is true may not be provable and many things which are provable may not be true. This is why it's equally as important to hone your skills of discernment, and practice reckoning as well as reasoning. I think of it as hearing "a ring of truth," but this is obviously unfalsifiable and I must remain skeptical against myself when I believe I hear this. It should be a guide toward deeper investigation, not the final destination.
Many people are led astray by thinking. It is seductive. It should be more commonly said that thinking is but a conscious stumbling block on the way to unconscious perfection.