Never assume the obvious is true. William Safire
We must never assume that which is incapable of proof. G H Lewes
Pride is increased by ignorance; those assume the most who know the least. John Gay
You must stick to your conviction, but be ready to abandon your assumptions. Denis Waitley
What a man believes may be ascertained, not from his creed, but from the assumptions on which he habitually acts. George Bernard Shaw
The criterion of simplicity requires that the minimum number of assumptions be postulated. Albert Low
It is always safe to assume that people are more subtle and less sensitive than they seem. Eric Hoffer