How Can You Be Certain

Give Me Extension And Motion And I Will Construct The Universe.

I Accept No Principles Of Physics Which Are Not Also Accepted In Mathematics.

Intuitive Knowledge Is An Illumination Of The Soul, Whereby It Beholds In The Light Of God Those Things Which It Pleases Him To Reveal To Us By A Direct Impression Of Divine Clearness.

How Do We Know That Anything Really Exists, That Anything Is Really The Way It Seems Ot Us Through Our Senses?

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