It must be conceded that a theory has an important advantage if its basic concepts and fundamental hypotheses are 'close to experience,' and greater confidence in such a theory is certainly justified. There is less danger of going completely astray, particularly since it takes so much less time and effort to disprove such theories by experience. Yet more and more, as the depth of our knowledge increases, we must give up this advantage in our quest for logical simplicity in the foundations of physical theory.
Enlightenment is the liberation of man from his self-caused state of minority... Supere aude! Dare to use your own understanding!is thus the motto of the Enlightenment.
The reasons for which 'this' world has been characterized as 'apparent' are the very reasons which indicate its reality; any other kind of reality is absolutely indemonstrable.
We live in a system of approximations. Every end is prospective of some other end, which is also temporary; a round and final success nowhere. We are encamped in nature, not domesticated.
But this is that which will dignify and exalt knowledge: if contemplation and action be more nearly and straitly conjoined and united together than they have been: a conjunction like unto that of the highest planets, Saturn, the planet of rest and contemplation, and Jupiter, the planet of civil society and action.
The science [geometry] is pursued for the sake of the knowledge of what eternally exists, and not of what comes for a moment into existence, and then perishes.