Further, as we shall show, during his last or Eustochian period after Porphyry had taken a trip to Sicily to avoid suicide, he himself was to return to Numenian standpoints. This may be shown in a general way as follows. Of the nine Eustochian essays[582] only two[583] betray no similarities to Numenian ideas, while seven[584] do. On the contrary, in the Amelio-Porphyrian period,[585] written immediately on Amelius's dismissal, only six[586] are Numenian, and six[587] are non-Numenian. In the succeeding wholly Porphyrian period,[588] we have the same equal number of Numenian[589] and non-Numenian[590] books. An explanation of this reversion to Numenian ideas has been attempted in the study of the development in Plotinos's views. On the whole, therefore, Plotinos's opposition to Numenius may be considered no more than episodic. 4. DIRECT INDEBTEDNESS OF PLOTINOS TO NUMENIUS. As Plotinos was in the habit of not even putting his name to his own notes; as even in the times of Porphyry the actual authorship of much that he wrote was already disputed; as even Porphyry acknowledges principles and quotations were borrowed, we must discover Numenian passages by their content, rather than by any external indications. As the great majority of Numenius's works are irretrievably lost, we may never hope to arrive at a final solution of the matter; and we shall have to restrict ourselves to that which, in Plotinos, may be identified by what Numenian fragments remain. What little we can thus trace definitely will give us a right to draw the conclusion to much more, and to the opinion that, especially in his Amelian period, Plotinos was chiefly indebted to Numenian inspiration. We can consider[591] the mention of Pythagoreans who had treated of the intelligible as applying to Numenius, whose chief work was "On the Good," and on the "Immateriality of the Soul." The first class of passages will be such as bear explicit reference to quotation from an ancient source. Of such we have five: "That is why the Pythagoreans were, among each other, accustomed to refer to this principle in a symbolic manner, calling him 'A-pollo,' which name means a denial of manifoldness."[592] "That is the reason of the saying, 'The ideas and numbers are born from the indefinite doubleness, and the One;' for this is intelligence."[593] "That is why the ancients said that ideas are essences and beings."[594] "Let us examine the (general) view that evils cannot be destroyed, but are necessary."[595] "The Divinity is above being."[596] A sixth case is, "How manifoldness is derived from the First."[597] A seventh case is the whole passage on the triunity of the divinity, including the term "Father."[598] Among doctrines said to be handed down from the ancient philosophers[599] are the ascents and descents of souls[600] and the migrations of souls into bodies other than human.[601] The soul is a number.[602]