St. Thomas and reflex principles

[ptlopes]

Hello,

Garrigou-Lagrange writes about conscience and probabilism in Reality:

St. Thomas, it is true, does cite at times other reflex principles, useful in forming conscience, for example, that in doubt we are to stand by the view which is presumably true. But if he seldom dwells on these reflex principles, it is because he holds that prudential certitude¹⁰³⁹ is found in that view which is nearest to evident truth, and most in conformity, not with egoism, but with the inclination to virtue.

Where does St. Thomas teach the principle that "in doubt we are to stand by the view which is presumably true"?

Thanks.
God bless,
Pedro

[Geremia]

Where does St. Thomas teach the principle that "in doubt we are to stand by the view which is presumably true"?

Garrigou-Lagrange, O.P., cites Summa Theologica I-II q. 57 a. 5 ad 3, which contains the famous axiom:

Verum [...] intellectus practici accipitur per conformitatem ad appetitum rectum.
[T]he truth of the practical intellect depends on conformity with right appetite.

• Garrigou-Lagrange, O.P., The Order of Things: The Realism of the Principle of Finality ch. 6 "Moral Realism: Finality and the Formation of Conscience" discusses this axiom.
• Wuellner, S.J., Summary of Scholastic Principles pp. 67-8, regarding "Reflex solutions" to resolving practical doubt, cites Summa Theologica I-II q. 19 a. 6 "Whether the will is good when it abides by erring reason?"
• Cf. also the overview of probabilism, equi-probabilism, and probabiliorism, etc., in Merkelbach, O.P., Summa Theologiæ Moralis (vol. 2): De virtutibus moralibus pp. 70-2.

[ptlopes]

Hello Geremia,

Isn't Garrigou-Lagrange talking about the reflex principle "when in doubt one must stand by presumption"?

"[T]he truth of the practical intellect depends on conformity with right appetite" isn't a reflex principle, if I'm not mistaken.

Best regards,
Pedro

[Geremia]

"[T]he truth of the practical intellect depends on conformity with right appetite" isn't a reflex principle

That's true, but reflex principles follow from it / are an application of it.

[ptlopes]

How is the reflex principle we're talking about an application of the other principle? I never read about that. 

Thank you for tour answers.

[Geremia]

How is the reflex principle we're talking about an application of the other principle?

Read

Garrigou-Lagrange, O.P., The Order of Things: The Realism of the Principle of Finality ch. 6 "Moral Realism: Finality and the Formation of Conscience"

It discusses reflex principles.