Duns Scotus
(1266 - 1308)
Duns Scotus, following Aristotle (Metaphysics Ch 2, 982 B 1), asks what are the most general things we know about everything that exists: what are the "prime knowables?" This creates a universal science that he calls metaphysics.
Since they are common to all things, the prime knowables are presupposed by all knowledge of “special” objects. The most general aspects of being ("communissima") must be known beforehand, or known a priori. They are the theme of a universal science that pertains to what is ‘most common’ to all the particular sciences insofar as what is thereby shared exceeds the determination of each of these sciences, but is nevertheless necessarily implied by them. This universal science studies the transcendentals and is what we call metaphysics.
Duns Scotus subsequently argues for four, rather than three, speculative sciences: physics, mathematics, theology, are all special sciences, and then there is also a science that precedes them as their foundation. This is metaphysics, which is a "scientia transcendens," a science of Being.
But for there to be a universal science of Being, it must have an unequivocal concept of Being. But is Being, or beings (ens), an unequivocal concept? No, answers Thomas, and Yes, answers Scotus. Unlike Thomas, Scotus says that even when speaking of God, we only have a concept of Being that is common to God and to creatures. He writes:
Every intellect that is certain about one concept, but dubious about others has, in addition to the concepts about which it is in doubt, another concept of which it is certain.… A man can be certain in his mind that God is a being and still be in doubt whether He is a finite or an infinite being, a created or uncreated being. Consequently, the concept of ‘Being’ as affirmed of God is different from the other two concepts but is included in both of them and therefore is unequivocal. (Duns Scotus, “Man’s Natural Knowledge of God,” 20 (Ordinatio I, 3, 26).)
Scotus, unlike Thomas, refuses to make the distinction between esse and essence. For him, “it is simply false that Being is other than essence.” Scotus contests the idea of a real distinction between essence and Being (or existence). A logical (or nominal) distinction is one of thought, a real distinction is a distinction between two different “things.”
For Duns Scotus, Being is nothing other than essence, conceived as a “common nature.” Yet, an existing common nature is no more than an actually realized essence, which exists as a mode of effective existence that is in itself indifferent to any common nature. The distinction between essence and existence is therefore not a real difference, but a “mode” (modus). Existence is simply “a modality of essence.” This leads to the expression “modes of being."
Duns Scotus reinstates the Aristotelian primacy of essence (or eidos) over existence, but he is also one of the first thinkers of Western Philosophy who argued for a first, universal and unequivocal science of Being or beingness.
Summary:
Only analogical or unequivocal knowledge of Being as such?
For there to be a universal science of Being, it must have an unequivocal concept of Being. But is Being, or beings (ens), an unequivocal concept? Yes, answers Scotus. Unlike Thomas, Scotus says that even when speaking of God, one cannot but have a concept of Being that is common to God and to creatures.
Duns Scotus starts to distinguish the concepts of transcendence and transcendental.
He speaks of a transcendent science (transcendens), but others will later speak more readily of a transcendental science (transcendentalis).
Four speculative sciences: Other than physics, mathematics and theology, which are all special sciences (speciales), there is also a science that precedes them as their foundation. This is the alia metaphysica, the “other metaphysics,” which is a scientia transcendens, a science of the “transcendens”—that is, of Being.
What Duns Scotus means by “Being” is essence or quiddity, the seat of the ens. The reason is that Scotus, unlike Thomas, refuses to make the distinction between esse and essence. For him, “it is simply false that Being is other than essence.”
Are the distinctions we make between being and essence real, or are they just nominal, i.e. distinction in our minds?
Scotus thus contests the idea of a real distinction between essence and Being (or existence). Whereas a logical (or nominal) distinction is one of thought, a real distinction is a distinction between two different “things.
Distinction between general and special metaphysics: ontology, transcendentalis on one side, psychology, cosmology, theology on the other.
Modernity radicalizes the marginalization of theology begun during the late Middle Ages.
After Kant, the term “transcendental philosophy” has different connotations. Since Kant, it is used to designate a reflection on the “conditions of the possibility of things.” These conditions are usually found in the constitution of the knowing subject (and, more recently, in the structure of language).
Insofar as the knowing, and speaking, subject contains the condition of possibility of things, philosophy that examines the subject as the condition or foundation of the intelligibility of things can claim the status of transcendental philosophy.
The medieval meaning of transcendental philosophy still lurks in the background: Modern transcendental philosophy still deals with the universal predicates of all that is. The only difference is that these predicates stem less from Being, or from God, and more from the subject that knows and thinks Being.