“Every injustice is the taking away of a good. There is no other good than virtue: but virtue cannot be taken away: thus it is not possible that the virtuous can suffer injustice from the wicked. It now remains either that no injustice can be suffered, or that it is suffered by the wicked from the wicked. But the wicked man possesses no good at all, for only virtue is a good; therefore none can be taken from him. Thus he also can suffer no injustice. Thus injustice is an impossible thing.” The original, which is less concise through repetitions, runs thus: “Αδικια εστι αφαιρεσις αγαθου; το δε αγαθον τι αν ειη αλλο η αρετη?—ἡ δε αρετη αναφαιρετον. Ουκ αδικησεται τοινυν ὁ την αρετην εχων, η ουκ εστιν αδικια αφαιρεσις αγαθου; ουδεν γαρ αγαθον αφαιρετον, ουδ᾽ χαποβλητον, ουδ ἑλετον, ουδε ληιστον. Ειεν ουν, ουδ᾽ αδικειται ὁ χρηστος, ουδ ὑπο του μοχθηρου; αναφαιρετος γαρ. Λειπεται τοινυν η μηδενα αδικεισθαι καθαπαξ, η τον μοχθηρον ὑπο του ὁμοιου; αλλα τῳ μοχθηρῳ ουδενος μετεστιν αγαθου; ἡ δε αδικια ην αγαθου αφαιρεσις; ὁ δε μη εχων ὁ, τι αφαιρεσθη, ουδε εις ὁ, τι αδικησθη, εχει” (_Sermo 2_). I shall add further a modern example of such proofs from abstract conceptions, by means of which an obviously absurd proposition is set up as the truth, and I shall take it from the works of a great man, Giordano Bruno. In his book, “_Del Infinito Universo e Mondi_” (p. 87 of the edition of A. Wagner), he makes an Aristotelian prove (with the assistance and exaggeration of the passage of Aristotle’s _De Cœlo_, i. 5) that there can be _no space_ beyond the world. The world is enclosed by the eight spheres of Aristotle, and beyond these there can be no space. For if beyond these there were still a body, it must either be simple or compound. It is now proved sophistically, from principles which are obviously begged, that no _simple_ body could be there; and therefore, also, no compound body, for it would necessarily be composed of simple ones. Thus in general there can be no body there—but if not, then _no space_. For space is defined as “that in which bodies can be;” and it has just been proved that no body can be there. Thus there is also there no space. This last is the final stroke of this proof from abstract conceptions. It ultimately rests on the fact that the proposition, “Where no space is, there can be no body” is taken as a universal negative, and therefore converted simply, “Where no body can be there is no space.” But the former proposition, when properly regarded, is a universal affirmative: “Everything that has no space has no body,” thus it must not be converted simply. Yet it is not every proof from abstract conceptions, with a conclusion which clearly contradicts perception (as here the finiteness of space), that can thus be referred to a logical error. For the sophistry does not always lie in the form, but often in the matter, in the premisses, and in the indefiniteness of the conceptions and their extension.