The first paralogism concerns the substantiality and immortality of the soul. It addresses whether our experience of the “I“ as an object of our inner sense is sufficient to determine either its immortality or substantiality. According to the classical view, a substance is the subject of the accidents (such as it’s color, weight, motility, and extension in space) that inhere in it. Furthermore, because it is the (ontological) subject of the inherence of these attributes, a substance may also be considered the grammatical (or logical) subject of our (propositional) judgments. Thus, in the phrase “Samson is drowsy,“ Samson is both a substance and the logical subject of the predicate said of it. Thus, classically speaking, substantiality entail two vectors: as a subject of accidents it bears an ontological relation to its attributes; as a grammatical subject, it bears a logical relation to the predicates that are said truly or falsely of it.
As mentioned in part one, the Cartesian soul likewise functions as a kind of subject/substrate of its judgments (e.g. it is the subject of the expression “I am thinking about P” as well as a substance) and in that sense it takes on all thoughts as accidents. For Kant, (as was said in part 1) the Cartesian I is reconstrued as the “Transcendental subject of the thoughts=X” that only becomes known to us by having an object.
Turning to the general introductory section of the Paralogisms, it can be seen that the Kantian “I” functions as the absolute/logical subject of predicates in much the same way that substance functions within the context of Aristotle‘s categories. As he writes, “it is known only through the thoughts which are its predicates“ (B404).
But for Kant the application of the criterion of subjecthood to substance is not a straightforward one. In Paralogisms A (the first edition ) Kant makes room for considering the soul a substance, but with qualifications. He writes that while we may consider the substrate that underlies the “I” a substance, we must recognize that the “concept signifies a substance only in idea, not in reality“ (A351). Thus, Kant applies his phenomenal/noumenal distinction to our idea of the soul.
His rule, to put it simply, is that any concept that lacks a correlate in our experience cannot be considered a real object. It is only by being represented to us phenomenally that an object can be considered a reality for us. Such objects do not have reality of themselves, are not things in themselves, but come to be real for us by being phenomenally presented to us. This divide between pure concepts and the possibility of their reality for us is consistent with the negative sense of the term “noumenon,“ which requires a sharp divide between concepts and objects, so that we do not fall into the error of talking about pure concepts as though they were things.
For Kant we certainly have an inner experience of the soul. It is the subject of all of the thoughts that the “I” happens to have. But it is not something of which we have any objective experience. For that reason, while we may conceptualize the soul as the subject of all the thoughts it has based upon our inner experience, it does not follow that it is therefore a substance, which is something only our outer experience could confirm. Kant writes,
we do not have, and cannot have, any knowledge whatsoever of any such subject. Consciousness is, indeed, that which alone makes all representations to be thoughts, and in it, therefore, as the transcendental subject, or perceptions must be found; but beyond this logical meaning of the ‘I,’ we have no knowledge of the subject in itself, which as substratum underlies this ‘I’ as it does all thoughts.“
A350
Whereas the philosophical tradition tends to treat anything that has the role of something that acts as the subject of predicates as a substance, Kant questions the straightforward application of a logical criterion to an ontological reality. That is to say, he questions, in effect, the assumption that appears embedded in Aristotle’s Categories that anything that qualifies as a logical subject can thereby be considered a substance. Now, if the very substantiality of the soul can be questioned, so, likewise, may it’s immortality. His his critique of the claim that it is immortal will be discussed as part of a further exploration of his treatment of the Cartesian “I.”
The Immortality of the Rational Soul
It is only a short march from restricting our notion of the soul to a negative noumenal concept to the further realization that other concepts that depend upon its substantiality do not follow. One of these is its immortality.
Again, the basis for our acceptance of anything as part of our reality, or as analytic philosophers once commonly phrased it, “into our ontology,” is the objective field of experience. Such objectivity is the foundation for the application of the pure categories of experience upon which our understanding may begin to form its concepts of things as we find them. But we have no “objective” experience of the soul in this sense: hence, no objective basis for considering it to be a substance. Now, if the soul is not a substance, it cannot be an immortal substance.
As was said above, this line of argumentation owes much to Hume. If we turn briefly to his treatise on human nature where he discusses personal identity, we find him attacking the Cartesian sense of the self at the outset.
There are some philosophers who imagine we are every moment intimately conscious of what we call our self; that we feel its existence, and it’s continuance in existence; and are certain, beyond the evidence of a demonstration, both of its perfect identity and simplicity.
T 1.4.6.1
As we have just seen, Kant argues in much the same vein. But it has also been seen that Kant does argue in favor of self perception, something that he calls apperception, so that he does not entirely dismiss the notion that we do have a sense of a self within us as the subject of our Thoughts and perceptions.
Whereas Hume argues that we have no idea of such a self among all our thoughts and sensory impressions, Kant argues that we do have an idea of a transcendental I that unifies our ideas. Because it is a Transcendental idea it cannot be something of which we have a clear and distinct impression, though we may have a concept of it. It is, of course, not this concept that justifies the claim that it exists, nor even our inner impression of a unification and association of our thoughts by some one thing, but it’s necessity for us to have a mental experience such as we have, which involves unifying not only perceptions, but concepts in an attempt to arrive at knowledge. It is the necessity of some source of unification within us, within the framework of our mental experience, that Kant takes as a basic datum that must be explained. it is the Transcendental I, rather than the Cartesian I, that satisfies both the rationalistic need for a principle underlying our mental experience, while acknowledging the force of Hume’s argument.
