In one work, this thinker used the example of Castor and Pollux sleeping in alternating shifts to demonstrate that the soul is not always thinking. A chapter in a work by this thinker contrasts certain knowledge with arguments that are likely to be true based on “probability,” or agreement between our own and others’ experiences. This thinker described a central concept being affected by sensory experiences of intrinsic “primary qualities” (10[1])and subjective “secondary qualities.” (10[2])This thinker argued that reflection or sensation informs all “objects of thinking” to refute “innate ideas” in favor of the human mind as a blank slate, or (10[1])tabula (10[1])rasa. For 10 points, (10[1])name this Enlightenment philosopher who wrote An Essay Concerning Human Understanding. ■END■