Rene Descartes

1. Asked questions like

1.1. How do we know we're not in a dream?

1.2. How reliable are our senses?

1.3. Is there a supreme being?

2. And awnsered all these questions via

2.1. Rationalism

2.1.1. Which involves:

2.1.1.1. Taking what you know and putting it through the process of Radical Doubt

2.1.1.2. The apple basket idea

2.1.1.2.1. The idea that all your beliefs are apples in a basket and in order to know the truth, one must empty the basket and making sure the apples are not rotton. and only the apples that are not rotton will return to the basket as concrete, undeniable knowledge.

2.1.1.2.2. Turns out very few beliefs pass the test of radical doubt.

2.1.1.3. Forgetting everything you thought you knew