2. Analytical Introduction (4)

2. Definition of logic
2.1 Determining the genus
2.1.1 Logic as science and art

a) Preliminary notions

1. science: cf supra
2. art
In the greco-medieval view, the notion of art meant a certain intellectual habitude (habitus)which concerned things to be made. It is therefore defined as recta ratio factibilium. In a strict sense, what is to be made encompasses every external product (house, ship, etc); taken in a wider sense however, it encompasses also internal products (calculations, reasonings, etc). External products are the object of the mechanical arts, while the internal products are the object of the liberal arts.

3. conditions necessary to be the object of an "art"
i) It is necessary that the making of a product implies a certain indetermination. For example, there is between seeing a table and making a table this difference, that the act of seeing the table is totally determined by nature, while the action of making the table is inderterminate, and so can fail. The habitus if art serves to remove this indetermination, proposing rules and directions to make the determined product.
ii) It is necessary that the product being made be guided by certain means and determinations to reach the end of realizing the art, that is universal means. Otherwise the art could not remove the indetermination of the product to be made: one would need to invent an art every single time which would be the same as not having one. In art, determination of the laws takes away the indetermination of the product.

b) Thesis
1. statement: Logic is both a science and a liberal art
2. demonstration:
i) science
m Logic scrutinizes the products proper to each act of the mind, knows their nature and deduces universal rules;
M But to establish universal rules from the being of a thing is proper to science;
C therefore logic is a science.
(St Thomas various times calls logic a science. Cf. SM 1,lect. 1, n. 32: "quaedam [artes sint] vero ad introductionem in aliis scientiis, sicut scientiae logicales"; cf also SM 1, lect. 3, n. 57

ii) art
logic responds to the conditions of art:
- in reasoning, there is a certain indetermination. Although in fact the act of reason is ordered in itself to the true, there is also the possibility of error, which shows a certain indetermination, due to the discursive character of our intelligence (neither God nor angels need logic!). If error is possible, there is also the possibility of something to help us avoid such error.
- Reason can be guided by certain fixed, necessary and universal rules (like those of the syllogism*).
C The two conditions are present in reasoning because logic is a liberal art.

* Cf II-II,47,2,3m: "omnis applicatio rationis rectae ad aliquid factibile pertinet ad artem. (...) Quia igitur ratio speculativa quaedam facit, puta syllogismum, propositionem et alia huiusmodi, in quibus proceditur secundum certas et determinatas vias; inde est quod respectu horum potest salvari ratio artis"
"Every application of right reason in the work of production belongs to art: (...) Since then, the speculative reason makes things such as syllogisms, propositions and the like, wherein the process follows certain and fixed rules, consequently in respect of such things it is possible to have the essentials of art"
Cf also I-II,57,3,3m: "etiam in ipsis speculabilibus est aliquid per modum cuiusdam operis, puta constructio syllogismi aut orationis congruae aut opus numerandi vel mensurandi. Et ideo quicumque ad huiusmodi opera rationis habitus speculativi ordinantur, dicuntur per quandam similitudinem artes, sed liberales"
"Even in speculative matters there is something by way of work: e.g. the making of a syllogism or of a fitting speech, or the work of counting or measuring. Hence whatever habits are ordained to such like works of the speculative reason, are, by a kind of comparison, called arts indeed, but “liberal” arts"