Metaphysical Essence of God
I.e., “the fundamental note of the Deity which distinguishes It from all created things, and which is the source and origin of all the other Divine perfections” [Ott 25]
Scotus: Radical infinity
Aquinas: Aseity, Subsistent Being [ST I, q. 13, art. 11, corp.]: This name HE WHO IS is most properly applied to God … For it does not signify form, but simply existence itself. Hence since the existence of God is His essence itself, which can be said of no other (3, 4), it is clear that among other names this one specially denominates God, for everything is denominated by its form.
Distinction of Divine Attributes
It is heresy to hold that the attributes of God are really distinct from one another [Ott 28-29], that is, that God’s justice is distinct from His mercy as a thing (res) differs from another thing, as if it was logically possible for His justice to exist without His mercy.
Scotus: The divine attributes are formally distinct (distinctio formalis a parte rei), i.e., they are really identical but, prior to the act of our intellect, have different characters (rationes) that do not overlap each other [Jeffrey Hause]. To use Michael Sullivan’s illustration, God’s idea of a cat is really identical with God’s idea of a dog, but the character of His idea of a cat is not identical with the character of His idea of a dog, since cats and dogs are really different, not merely distinct by reason reasoning (without a foundation in reality).
Aquinas: The divine attributes are distinct by a minor virtual distinction (of reasoned reason) with a foundation in reality (distinctio virtualis minor or rationis ratiocinatae sive cum fundamento in re), i.e., they are really identical and each attribute implicitly includes the other attributes, but we can only know the one divine reality “under many and different aspects” or concepts [ST I, q. 13, art. 4, corp.].
Would the Holy Spirit be hypostatically distinct from the Son if He did not proceed from the Son?
Scotus: Yes [Commentary on the Sentences b. I, d. 11, q. 2 (Wadding IX:843)]
Aquinas: No [ST I, q. 36, art. 2]
How Many Sonships (Filiations) in Christ?
Scotus: Two [Commentary on the Sentences b. III, d. 8, q. 1]
Aquinas: One [ST III, q. 35, art. 5, corp.]: If we consider the adequate causes of filiation, we must needs say that there are two filiations in respect of the twofold nativity. But if we consider the subject of filiation, which can only be the eternal suppositum, then no other than the eternal filiation in Christ is a real relation.
Can Angels Naturally Know Men’s Secret Thoughts?
Scotus: Yes 
Aquinas: No [ST I, q. 57, art. 4, corp.]: “In another way thoughts can be known as they are in the mind, and affections as they are in the will: and thus God alone can know the thoughts of hearts and affections of wills.”
Could Innocent Adam Sin Venially?
Scotus: Yes [Commentary on the Sentences b. II, d. 21, q. 1 (Wadding XIII:135)]
Aquinas: No [ST II-I, q. 89, art. 3, corp.]: In the state of innocence, as stated in the I, 95, 1, there was an unerring stability of order, so that the lower powers were always subjected to the higher, so long as man remained subject to God, as Augustine says (De Civ. Dei xiv, 13). Hence there can be no inordinateness in man, unless first of all the highest part of man were not subject to God, which constitutes a mortal sin. From this it is evident that, in the state of innocence, man could not commit a venial sin, before committing a mortal sin. Cf. Commentary on the Sentences b. II, d. 21, q. 2, art. 3, corp.
Is the Venial Sin of the Lost Punished Forever?
Scotus: No 
Aquinas: Yes [ST II-I, q. 87, art. 5, ad 2-3]: Venial sin “incurs everlasting punishment, not on account of its gravity, but by reason of the condition of the subject, viz., a human being deprived of grace, without which there is no remission of sin.” Cf. Commentary on the Sentences b. II, d. 42, q. 1, art. 5, ad 6.
Can an individual action be indifferent?
Aquinas: No [ST II-I, q. 18, art. 9, corp.] : “It must needs be either directed or not directed to a due end. Consequently every human action that proceeds from deliberate reason, if it be considered in the individual, must be good or bad.”