In spite of the fact that the earlier theory that no commercial gain which did not represent payment for labour could be justified was still maintained by some writers--for instance, Raymond de Pennafort[1]--the teaching of St. Thomas Aquinas was generally accepted throughout the later Middle Ages. Canonists and theologians accepted without hesitation the justification of trade formulated by Aquinas.[2] Henri de Gand,[3] Duns Scotus,[4] and François de Mayronis [5] unhesitatingly accepted the view of Aquinas, and incorporated it in their works.[6] 'An honourable merchant,' says Trithemius, 'who does not only think of large profits, and who is guided in all his dealings by the laws of God and man, and who gladly gives to the needy of his wealth and earnings, deserves the same esteem as any other worker. But it is no easy matter to be always honourable in all mercantile dealings and not to become usurious. Without commerce no community can of course exist, but immoderate commerce is rather hurtful than beneficial, because it fosters greed of gain and gold, and enervates and emasculates the nation through love of pleasure and luxury.'[7] Nider says that to buy not for use but for sale at a higher price is called trade. Two special rules apply to this: first, that it should be useful to the State, and second, that the price should correspond to the diligence, prudence, and risk undertaken in the transaction.[8] [Footnote 1: _Summa Theologica_, II. vii. 5.] [Footnote 2: Ashley, _op. cit._, p. 55.] [Footnote 3: _Quodlib_., i. 40.] [Footnote 4: _Lib. Quat. Sent._, xv. 2.] [Footnote 5: iv. 16, 4.] [Footnote 6: See Jourdain, _op. cit._, p. 20 _et seq_.] [Footnote 7: Quoted in Janssen, _op. cit._, vol. ii. p. 97.] [Footnote 8: _Op. cit._, iv. 10.] The later writers hi the fifteenth century seem to have regarded trade more liberally even than Aquinas, although they quote his dictum on the subject as the basis of their teaching. Instead of condemning all commerce as wrong unless it was justified by good motives, they were rather inclined to treat commerce as being in itself colourless, but capable of becoming evil by bad motives. Carletus says: 'Commerce in itself is neither bad nor illegal, but it may become bad on account of the circumstances and the motive with which it is undertaken, the persons who undertake it, or the manner in which it is conducted. For instance, commerce undertaken through avarice or a desire for sloth is bad; so also is commerce which is injurious to the republic, such as engrossing.'[1] [Footnote 1: _Summa Angelica_, 169: 'Mercatio non est mala ex genere, sed bona, humano convictui necessaria dum fuerit justa. Mercatio simpliciter non est peccatum sed ejus abusus.' Biel, _op. cit._, iv. xv. 10.]