mindless -
lacking the thinking capacity characteristic of a conscious being; "the shrieking of the mindless wind"
meaningless,
nonmeaningful having no meaning or direction or purpose; "a meaningless endeavor"; "a meaningless life"; "a verbose but meaningless explanation"
mindful,
aware bearing in mind; attentive to; "ever mindful of her health"; "mindful of his responsibilities"; "mindful of these criticisms, I shall attempt to justify my action"