Belinda;
How might we avoid rationalising while preserving reasoning?
It is damn near impossible to avoid Rationalizing. A Rationalization being born of the Imagination, an Illusion of Reality.
An Illusion does not exist unless mistaken to be a Reality.
Solution; do not accept, believe that an Illusion is a Reality, that however is not to say that the possibility does not exist.
My best example is the Big Bang Theory; Many accept the Big Bang as being a Reality, not the Rationalization , theory, that it is.
A Rationalization is very Guileful because there is a great amount of truth in the formulation of the Theory of an Expanding Universe.
The proofs of an Expanding Universe, Red Shift, is offered up as Proof of an Expanding Universe; the Expanding Universe being offered up as Proof of the Theory of the Big Bang.
The Theory of the Big Bang was not formulated until after the "acceptance that the Theory of an Expanding Universe as being fact.
Redshift, the main evidence presented to prove that the Universe is expanding, which is the main proof of the Theory of the Big Bang.
Redshift is a fact, however Redshift does not prove that the Universe is expanding, was, is caused by the so called Big Bang.
There is, was, a huge demonstration in Washington touting the empirical evidence of Science, said demonstration being nothing more than a circle jerk.
Blasphemy, Hogwash, just so much Babble!
Theorize, conjecture, Speculate, Imagine, but do not believe what your eyes can not see is a Fact.
Not believing what your eyes can not see, meaning collect your know from many sources, not the Single source of knowledge Imagined to be the true source of Knowledge, the Rational Mind.
If thine single eye, thy mind's eye, be filled with darkness how great then is the Evil Within.
Rationalization, Guilefulness, is the Greatest Cause of all Unnecessary Suffering, is Evil.
-- Updated April 24th, 2017, 8:18 am to add the following --
Do not believe in the things that your eyes can not see, meaning that knowing must be glean from many sources, not the Single source of knowledge Imagined to be the true source of Knowledge, the Rational Mind.
If thine single eye, thy mind's eye, be filled with darkness how great then is the Evil Within.
Do not eat of the Fruit of the Tree of the Knowledge of Good and Evil, the Rational Mind, the Generator of Absolutely Bad Knowledge, Theory, Speculation, Conjecture.
The "Knowledge" of Reality is not Reality itself.