[72] Ibid. b. 12: πρὸς δὲ τοὺς ἐξ ὑποθέσεως συλλογσισμούς, διότι ἔνδοξόν ἐστιν, ὥς ποτε ἐφ’ ἑνὸς τῶν ὁμοίων ἔχει, οὕτως καὶ ἐὶ τῶν λοιπῶν· ὥστε πρὸς ὅ τι ἂν αὐτῶν εὐπορῶμεν διαλέγεσθαι, προδιομολογησόμεθα, ὥς ποτε ἐπὶ τούτων ἔχει, οὕτω καὶ ἐπὶ τοῦ προκειμένου ἔχειν. δείξαντες δὲ ἐκεῖνο καὶ τὸ προκείμενον ἐξ ὑποθέσεως δεδειχότες ἐσόμεθα· ὑποθέμενοι γάρ, ὥς ποτε ἐπὶ τούτων ἔχει, οὕτω καὶ ἐπὶ τοῦ προκειμένου ἔχειν, τὴν ἀπόδειξιν πεποιήμεθα. For τὸ ἐξ ὑποθέσεως, compare Topic. III. vi. p. 119, b. 35.
[73] Topic. I. xviii. p. 108, b. 19.
[74] Topic. I. xviii. p. 108, b. 27: ὥστε τὸ κοινὸν ἐπὶ πάντων γένος ἀποδίδοντες δόξομεν οὐκ ἀλλοτρίως ὁρίζεσθαι. It will be recollected that all the work of Dialectic (as Aristotle tells us often) has reference to δόξα and not to scientific truth. “We shall seem to define not in a manner departing from the reality of the subjectâ€� is, therefore, an appropriate dialectic artifice.
II.
The First Book of the Topica, which we have thus gone through, was entitled by some ancient commentators τὰ πρὸ τῶν Τόπων — matters preliminary to the Loci. This is quite true, as a description of its contents; for Aristotle in the last words of the book, distinctly announces that he is about to enumerate the Loci towards which the four above-mentioned Organa will be useful.[75]
[75] Ibid. p. 108, b. 32: οἱ δὲ τόποι πρὸς οὓς χρήσιμα τὰ λεχθέντα οἵδε εἰσίν.
Locus (τόπος) is a place in which many arguments pertinent to one and the same dialectical purpose, may be found — sedes argumentorum. In each locus, the arguments contained therein look at the thesis from the same point of view; and the locus implies nothing distinct from the arguments, except this manner of view common to them all. In fact, the metaphor is a convenient one for designating the relation of every Universal generally to its particulars: the Universal is not a new particular, nor any adjunct superimposed upon all its particulars, but simply a place in which all known similar particulars may be found grouped together, and in which there is room for an indefinite number of new ones. If we wish to arm the student with a large command of dialectical artifices, we cannot do better than discriminate the various groups of arguments, indicating the point of view common to each group, and the circumstances in which it becomes applicable. By this means, whenever he is called upon to deal with a new debate, he will consider the thesis in reference to each one of these different loci, and will be able to apply arguments out of each of them, according as the case may admit.
The four Helps (ὄργανα) explained in the last book differ from the Loci in being of wider and more undefined bearing: they are directions for preparatory study, rather than for dealing with any particular situation of a given problem; though it must be confessed that, when Aristotle proceeds to specify the manner in which the three last-mentioned helps are useful, he makes considerable approach towards the greater detail and particularization of the Loci. In entering now upon these, he reverts to that quadruple classification of propositions and problems (according to the four Predicables), noted at the beginning of the treatise, in which the predicate is either Definition, Proprium, Genus, or Accident, of the subject. He makes a fourfold distribution of Loci, according as they bear upon one or other of these four. In the Second and Third Books, we find those which bear upon propositions predicating Accident; in the Fourth Book, we pass to Genus; in the Fifth, to Proprium; in the Sixth and Seventh, to Definition.
The problem or thesis propounded for debate may have two faults on which it may be impugned: either it may be untrue; or it may be expressed in a way departing from the received phraseology.[76] It will be universal, or particular, or indefinite; and either affirmative or negative; but, in most cases, the respondent propounds for debate an affirmative universal, and not a negative or a particular.[77] Aristotle therefore begins with those loci that are useful for refuting an Affirmative Universal; though, in general, the same arguments are available for attack and defence both of the universal and of the particular; for if you can overthrow the particular, you will have overthrown the universal along with it, while if you can defend the universal, this will include the defence of the particular. As the thesis propounded is usually affirmative, the assailant undertakes the negative side or the work of refutation. And this indeed (as Eudemus, the pupil of Aristotle, remarked, after his master[78]) is the principal function and result of dialectic exercise; which refutes much and proves very little, according to the analogy of the Platonic Dialogues of Search.
[76] Topic. II. i. p. 109, a. 27: διορίσασθαι δὲ δεῖ καὶ τὰς ἁμαρτίας τὰς ἐν τοῖς προβλήμασιν, ὅτι εἰσὶ διτταί, ἢ τῷ ψεύδεσθαι, ἢ τῷ παραβαίνειν τὴν κειμένην λέξιν.