[297] Ibid. a. 19-26.
[298] Topic. VI. vi. p. 145, a. 28-32. πρώτον γὰρ τοῦ λογιστικοῦ ἀρετὴ ἡ φρόνησις· κατὰ γὰρ τοῦτο καὶ ἡ ψυχὴ καὶ ὁ ἄνθρωπος φρονεῖν λέγεται.
13. When the definiend is given as an affection or lasting condition of some subject, you must examine whether it really resides or can reside (as by nature it ought to do) in the subject to which it is referred in the definition. If it cannot, the definition is untenable; and this mistake is sometimes made, the producing conditions of a phenomenon being confounded with the phenomenon itself, or vice versâ.[299] Thus, some persons have defined sleep — incapacity of sensible perception; doubt — equality of contrary reasonings; pain — breach of continuity violently made in parts of the organism which naturally grow together. Now sleep does not reside in perception, nor doubt in reasonings. Sleep is that which produces or occasions incapacity of sensible perception; doubt is a state of mind produced by equality of contrary reasonings.[300] This will be a locus for arguing against the definition.
[299] Ibid. b. 11: τὸ ποιούμενον εἰς τὸ ποιητικὸν ἢ ἀνάπαλιν συμβαίνει τιθέναι τοῖς οὕτως ὁριζομένοις.
[300] Ibid. a. 33-b. 20.
14. Another locus is, when the definiend has direct bearing and reference to something different from what is enunciated in the definition. Thus, if the respondent defines justice — a power tending to make equal distribution, you may remark hereupon, that the just man is he who is deliberately resolved to make equal distribution, not he who has the power to do so. If this definition were allowed, the justest man would be he who has the greatest power of so distributing.[301]
[301] Ibid. vii. p. 145, b. 34-p. 146, a. 2.
15. Again, the definition will be assailable, if the definiend admits graduation of More or Less, while that which is enunciated in the definition does not admit it, or vice versâ; also, if both of them admit graduation, but the variations of the two are not corresponding and concomitant. The defining phrase ought to be identical in signification with the term defined.[302] If both of them agree in reference to some common correlate, but one is to this in the relation of more while the other is in the relation of less, the definition is faulty.[303]
[302] Ibid. p. 146, a. 3-12. εἴπερ δὴ ταὐτόν ἐστι τὸ κατὰ τὸν λόγον ἀποδοθὲν τῷ πράγματι.
Here we have a principle of Concomitant Variations analogous to that which is so well unfolded, as one of the Four Inductive Methods, in Mr. J. S. Mill’s ‘System of Logic.’ See Book III. ch. viii. sect. 6.