What Comte chiefly condemned in the metaphysical mode of thought, are the conception of mental abstractions as real entities which exert power and produce phenomena, and the enunciation of these entities as explanations of the phenomena; and certainly 'it is,' as Mr. Mill says, or rather was, previously to his own ingenious solution of it, 'one of the puzzles of philosophy, how mankind, after inventing a set of mere names to keep together certain combinations of ideas and images, could have so far forgotten their own act as to invest these creations of their will with objective reality, and mistake the name of a phenomenon for its efficient cause.' Those natural laws, however, on which Positivism relies--are not they as purely mental abstractions as the essences, virtues, properties, forces, and what not, for which it is proposed to substitute them? Yet since Positivism regards these laws as 'governing' phenomena, and having phenomena 'subject' to them, must it not necessarily regard them likewise as realised abstractions, as real entities? Plainly, if its language be taken literally, its professors must acknowledge that it does, unless they prefer to stultify themselves by propounding such unmitigated nonsense as that power may be exercised, and phenomena produced, by _non_-entities. But if so, what else is Positivism than another form of that very metaphysicism which it condemns? and a form, too, peculiarly obnoxious to Mr. Mill's caustic remark that 'as in religion, so in philosophy, men marvel at the absurdity of other people's tenets, while exactly parallel absurdities remain in their own, and the same man is unaffectedly astonished that words can be mistaken for things, who is treating other words as if they were things every time he opens his mouth.'