(Latin: cause, reason, purpose; judicial process, lawsuit)

Et docere et rerum exquirere causas.
To teach and to inquire into the nature of things.

Motto of the University of Georgia, Athens, Georgia, USA.

excusable (adjective), more excusable, most excusable
Worthy of pardoning an error, oversight, etc.: When Thomas was late for school because of a doctor's appointment, it was an excusable reason that the teacher understood.
excusably (adverb), more excusably, most excusably
Characterizing how a person's wrong utterances or actions are forgiven or understood; pardonably: Lance was thought to be excusably late to the meeting since he had just returned from taking his mother to hospital for her operation.
Fac et excusa.
Do it and make excuses later.

Also, "Make your move." This is a motto for those who want to be a success in life.

Felix qui potuit rerum cognoscere causas.
Fortunate is he who has been able to learn the causes of things.

From Georglcs by Virgil who may have been praising the superior intelligence of those who can comprehend the secrets of nature and, as a result, avoid dependence on superstition to explain natural phenomena.

inexcusable (adjective), more inexcusable, most inexcusable
Relating to that which does not have justification or reason: Tommy was punished for his inexcusable rudeness towards his mother and was sent to his room without dinner or ice cream for dessert!
inexcusably (adverb), more inexcusably, most inexcusably
1. Pertaining to how a behavior is unpardonable: Tom was inexcusably rude towards his wife and treated her in an unforgivable way and soon after they were divorced.
2. Concerning how something is without any justification or reasonable explanation: Jack was known to be inexcusably late to all of his classes.