deliberately constructing out of a chaotic substratum the system of the Kosmos; and which also led him to unite with it the idea of a mode in which it acted on and through the primordial elements of matter. So that, from the class of philosophers to whom Lord Macaulay presumably referred as "the early Greeks," down to and including Plato, there was a great advance. The earlier Greek philosophers did not divide substance from its powers or properties, nor did they conceive of substance as a thing acted upon by power, or of power as a thing distinct from substance. They regarded substance, some primordial substance, with its powers and properties, as an efficient and material cause, and as the sole cause, as a positive and final agent. They did not seek for a final cause apart from the substances which they supposed to be the sole agents operating to produce important effects. But, inasmuch as they carried their various theories through nearly the whole range of possible speculation, they enabled Plato and Aristotle to see that there was a fundamental defect in their reasoning; that there must be an abstract conception of power as something distinct from substance or its properties. It was by Plato and Aristotle that this abstract conception was reached, of course without any influence of what we regard as revelation; and, although they did not always describe correctly the mode in which this power had acted, their perception of the logical necessity for such a final cause marks a great progress in philosophical speculation. It entirely refutes Lord Macaulay's assertion that natural theology is not a progressive science. It had made great progress from Thales to Plato; and while in a certain sense it is true that "a modern philosopher has before him just the same evidence of design in the structure of the universe which the early Greeks had"--that is, he has the same physical phenomena to observe--it is not true that the early Greeks did not develop conceptions of the origin of the universe valuable to their successors. Lord Macaulay should not have compared Thales with the modern philosopher, in respect of advantage of situation, but he should have compared the modern philosopher with Plato, and Plato with his predecessors; and if he had done this, he could not have asserted with any show of truth that natural theology has made no advance as a science from the time of Thales, the Milesian philosopher, and Simonides, the poet, to the present day. I shall have occasion hereafter to speak of the masterly intellectual power by which Plato wrought out his conception of a formative divine agency in the production of the Kosmos, and the bold and original speculation by which he avoided the charge of infidelity toward the established religion of his countrymen.