Quality is not a coincidence; it is a consequence.
Mental tranquility is the highest good.
The greatest obstacle to being heroic is the doubt whether one may not be going to prove one's self a fool; the truest heroism is to resist the doubt; and the profoundest wisdom, to know when it ought to be resisted, and when to be obeyed.
Every discovery in physics opens up a new realm of questions, reminding us that the pursuit of knowledge is an endless journey.