On the one hand, Descartes, a rationalist philosopher, identified ideas as those thoughts that “are as it were the images of things”. Moreover, he classifies ideas depending on their origin, pointing out that some appear to be innate, some to be adventitious, and others to have been invented by himself, but he highlights innateness as a faculty in mind, even the sensory ideas such as pains, colors and sounds.
On the other hand, Locke, who is an empirist thinker, argues that there are no innate ideas, as opposed to Descartes, but instead he believes all the materials of Reason and Knowledge are born from experience.
Thoughts on human consciousness:
Descartes believes consciousness as something “given”, as well as the ideas. He defines consciousness in terms of thoughts. He asserts that a thought is something "in us” that we are conscious of. In the <em>cogito ergo sum </em>(I think, therefore I am) argument, Descartes uses reason, once again, as a tool to doubt all features of his mind other than what is consciously available to him. As a consequence, his conscious thoughts don't give any further evidence that what they represent about things external to him either exist at all or exist as represented by the idea in his mind: consciousness becomes the mark of the mind.
Locke, like Descartes, also thinks consciousness in terms of thought: he believes one can't have a thought without being conscious of it. In addition, Locke further explains this idea exists only as far as experience will allow, since he does not believe that the soul always thinks, as other philosophers do, since people are not always conscious while asleep. Therefore, thinking is not the essence of the soul. The soul can persist through a state in which there is no thinking, but conscious depends on thinking so as to exist.
