In the second meditation, Descartes said, " I am therefore, precisely speaking, only a thinking thing, that is, a mind (mens sive animus), understanding, or reason, terms whose signification was before unknown to me. I am, however, a real thing, and really existent; but what thing? The answer was, a thinking thing." He understood that the only way he could believe he existed was by continuing to ask questions, thinking, and try to understand his rationality. He tested his new foundation by doing experiments. One of his experiments involved wax. I was perplexed by what the experiment meant until I read some of my classmates' posts. Kaitlyn's post was especially helpful because I was able to look at his experiment in a different way. She wrote,