There were thus, at Athens, three distinct parties inspired with unfriendly sentiment towards Aristotle: first, the Isokrateans; afterwards, the Platonists; along with both, the anti-Macedonian politicians. Hence we can account for what Themistius entitles the "army of assailants" ([Greek: stra/ton o(/lon]) that fastened upon him, for the unfavourable colouring with which his domestic circumstances are presented, and for the necessity under which he lay of Macedonian protection; so that when such protection was nullified, giving place to a reactionary fervour, his residence at Athens became both disagreeable and insecure. CHAPTER II. ARISTOTELIAN CANON. In the fourth and fifth chapters of my work on 'Plato and the Other Companions of Sokrates,' I investigated the question of the Platonic Canon, and attempted to determine, upon the best grounds open to us, the question, What are the real works of Plato? I now propose to discuss the like question respecting Aristotle. But the premisses for such a discussion are much less simple in regard to Aristotle than in regard to Plato. As far as the testimony of antiquity goes, we learn that the Canon of Thrasyllus, dating at least from the time of the Byzantine Aristophanes, and probably from an earlier time, was believed by all readers to contain the authentic works of Plato and none others; an assemblage of dialogues, some unfinished, but each undivided and unbroken. The only exception to unanimity in regard to the Platonic Canon, applies to ten dialogues, which were received by some (we do not know by how many, or by whom) as Platonic, but which, as Diogenes informs us, were rejected by agreement of the most known and competent critics. This is as near to unanimity as can be expected. The doubts, now so multiplied, respecting the authenticity of various dialogues included in the Canon of Thrasyllus, have all originated with modern scholars since the beginning of the present century, or at least since the earlier compositions of Wyttenbach. It was my task to appreciate the value of those doubts; and, in declining to be guided by them, I was at least able to consider myself as adhering to the views of all known ancient critics. Very different is the case when we attempt to frame an Aristotelian Canon, comprising all the works of Aristotle and none others. We find the problem far more complicated, and the matters of evidence at once more defective, more uncertain, and more contradictory.