Now, since our condition accommodates things to itself, and transforms them according to itself, we no longer know things in their reality; for nothing comes to us that is not altered and falsified by our Senses. When the compass, the square, and the rule are untrue, all the calculations drawn from them, all the buildings erected by their measure, are of necessity also defective and out of plumb. The uncertainty of our senses renders uncertain everything that they produce.
Michel de MontaigneWe cannot be held to what is beyond our strength and means; for at times the accomplishment and execution may not be in our power, and indeed there is nothing really in our own power except the will: on this are necessarily based and founded all the principles that regulate the duty of man.
Michel de Montaigne