How the world were delighted and wonder-struck by the supposed discovery, that it was the province of vegetable life to supply the vital air, which animal life destroyed! Priestley was hailed as the wonder of his age, and for a while its oracle. He was however no ordinary being, and even his enemies admitted him to be a kind and moral man. His intellectual powers will speak for themselves. We have now had sufficient experience to see how shifting all kind of theory must be when left to the will and ingenuity of man only--and how unsafe a guide in questions of importance as the one now referred to. Horsley saw the weak points of Priestley's argument, and was not to be dazzled and put aside by Priestley's philosophical display. Horsley fearlessly entered into this controversy, like a man who felt his own strength, and particularly the strength of his cause; though he needed not the courage of a Luther, he was apparently a man who possessed it, if called on. He used the best means to silence his adversary [27], with the Bible before him as his shield, (but at the same time his support as well as defence,) from behind which he assailed his opponent with his Biblical learning so powerfully, that his first attack made Priestley feel the strength of his adversary. In vaunting language, Priestley made the best defence which he thought he could, but not the most prudent, by promising to answer his opponent so efficiently, as to make him a convert to his doctrines. But in this vaunting prediction, that he would not only answer his opponent satisfactorily, to all who were interested in the controversy, but convert him to his opinions, it need not be added he failed, so completely, and at the same time displayed such a "ridiculous vanity," as to deprive him of that influence which he had so overrated in himself. Horsley's letters seem particularly to have attracted Coleridge's attention, and to have caused him to make one of his concise, pithy and powerful notes as a comment on this letter of Horsley's, entitled, "The Unitarian Doctrine not well calculated for the conversion of Jews, Mahometans, or Infidels, of any description." [28] The following is Coleridge's Comment on the Letter, to which allusion has been made, and from the date seems to have been written during his residence at Malta: