That in affairs of very ...

That in affairs of very considerable importance men should deal with one another with satisfaction of mind, and mutual confidence, they must receive competent assurances concerning the integrity, fidelity, and constancy each of other.
That in affairs of very considerable importance men should deal with one another with satisfaction of mind, and mutual confidence, they must receive competent assurances concerning the integrity, fidelity, and constancy each of other.
 Isaac Barrow

More phrases

Effort only fully releases its reward after a person refuses to quit.
Never complain and never explain.
A good plan violently executed now is better than a perfect plan executed next week.
 George S. Patton
Problems are not stop signs, they are guidelines.
 Robert Schuller
Never give up, for that is just the place and time that the tide will turn.
 Harriet Beecher Stowe

Quotes from the same author

Chance never writ a legible book; chance never built a fair house; chance never drew a neat picture; it never did any of these things, nor ever will; nor can it be without absurdity supposed able to do them; which yet are works very gross and rude, very easy and feasible, as it were, in comparison to the production of a flower or a tree.
 Isaac Barrow
An accomplished mathematician, i.e. a most wretched orator.
 Isaac Barrow
None are too wise to be mistaken, but few are so wisely just as to acknowledge and correct their mistakes, and especially the mistakes of prejudice.
 Isaac Barrow
He who loveth a book will never want a faithful friend, a wholesome counsellor, a cheerful companion, or an effectual comforter.
 Isaac Barrow