I was convinced that our beliefs are based much more on custom and example than on any certain knowledge.
Rene DescartesThe rainbow is such a remarkable phenomenon of nature, and its cause has been so meticulously sought after by inquiring minds throughout the ages, that I could not choose a more appropriate subject for demonstrating how, with the method I am using, we can arrive at knowledge not possessed at all by those whose writings are available to us.
Rene DescartesIntuition is the undoubting conception of a pure and attentive mind, which arises from the light of reason alone, and is more certain than deduction.
Rene DescartesNow therefore, that my mind is free from all cares, and that I have obtained for myself assured leisure in peaceful solitude, I shall apply myself seriously and freely to the general destruction of all my former opinions.
Rene DescartesIn God there is an infinitude of things which I cannot comprehend, nor possibly even reach in any way by thought; for it is the nature of the infinite that my nature, which is finite and limited, should not comprehend it.
Rene DescartesBut I cannot forget that, at other times I have been deceived in sleep by similar illusions; and, attentively considering those cases, I perceive so clearly that there exist no certain marks by which the state of waking can ever be distinguished from sleep, that I feel greatly astonished; and in amazement I almost persuade myself that I am now dreaming.
Rene Descartes