Friedrich Nietzsche quotes - page 31
If each us had a different kind of sense perception - if we could only perceive things now as a bird, now as a worm, now as a plant, or if one of us saw a stimulus as red, another as blue, while a third even heard the same stimulus as a sound - then no one would speak of such a regularity of nature, rather, nature would be grasped only as a creation which is subjective in the highest degree. After all, what is a law of nature as such for us? We are not acquainted with it in itself, but only with its effects, which means in its relation to other laws of nature - which, in turn, are known to us only as sums of relations. Therefore all these relations always refer again to others and are thoroughly incomprehensible to us in their essence.
Friedrich Nietzsche
It is true that there are men who, on the approach of severe pain, hear the very opposite call of command, and never appear more proud, more martial, or more happy than when the storm is brewing; indeed, pain itself provides them with their supreme moments! These are the heroic men, the great pain-bringers of mankind: those few and rare ones who need just the same apology as pain generally - and verily, it should not be denied them. They are forces of the greatest importance for preserving and advancing the species, be it only because they are opposed to smug ease, and do not conceal their disgust at this kind of happiness.
Friedrich Nietzsche