Scientific anticipations are commonly either truisms or failures; failures, if, as is usually the case, they are made upon insufficient data; and truisms, if they succeed, for conclusions, being always contained in their premisses, never can be discoveries. Yet, as mixed mathematics correct, without superseding, the pure science, so I do not see why I may not allowably take a sort of pure philosophical view of the Turks and their position, though it be but abstract and theoretical, and require correction when confronted by the event. There is a use in investigating what ought to be, under given suppositions and conditions, even though speculation and fact do not happen to keep pace together. As to myself, having laid down my premisses, as drawn from historical considerations, I must needs go on, whether I will or no, to the conjectures to which they lead; and that shall be my business in this concluding discussion. My line of argument has been as follows:--First, I stated some peculiarities of civilized and of barbarian communities; I said that it is a general truth that civilized states are destroyed from within, and barbarian states from without; that the very causes, which lead to the greatness of civilized communities, at length by continuing become their ruin, whereas the causes of barbarian greatness uphold that greatness, as long as they continue, and by ceasing to act, not by continuing, lead the way to its overthrow. Thus the intellect of Athens first was its making and then its unmaking; while the warlike prowess of the Spartans maintained their pre-eminence, till it succumbed to the antagonist prowess of Thebes. 1.