I Know That I Exist;

Everybody Thinks Himself So Well Supplied With Common Sense That Even Those Most Difficult To Please. . . Never Desire More Of It Than They Already Have.

Illusory Joy Is Often Worth More Than Genuine Sorrow.

The Only Thing We Have Power Over In The Universe Is Our Own Thoughts.

If I Simply Refrain From Making A Judgment In Cases Where I Do Not Perceive The Truth With Sufficient Clarity And Distinctness, Then It Is Clear That I Am Behaving Correctly And Avoiding Error.

Mathematics Is A More Powerful Instrument Of Knowledge Than Any Other That Has Been Bequeathed To Us By Human Agency.