Descartes' method of doubt steps
Methodic doubt example!
René Descartes () is an example of a rationalist. According to Descartes, before we can describe the nature of reality (as is done in metaphysics) or say what it means for something to be or exist (which is the focus of ontology), we must first consider what we mean when we say we know what reality, being, or existence is.
He suggests that it is pointless to claim that something is real or exists unless we first know how such a claim could be known as a justified true belief.
René descartes discoveries
But to say that our beliefs are justified, we have to be able to base them ultimately on a belief that is itself indubitable. Such a belief could then provide a firm foundation on which all subsequent beliefs are grounded and could thus be known as true.
This way of thinking about knowledge is called foundationalism.
In his Meditations on First Philosophy (), Descartes indicates how we are able to guarantee our beliefs about reality by limiting what we believe to what is in
