“Let the earth produce all kinds of living beings: cattle, reptiles and wild animals of all kinds. And so it came to pass: God created all sorts of wild animals, all sorts of cattle and all sorts of creeping things of the earth. God saw how good it was. (Genesis 1:20-25)
This is the intention of this two-part thesis to argue that at least some species of non-human animals possess immaterial, and therefore immortal, souls. This position is certainly not popular and not generally accepted within Catholic theology. I therefore ask the reader’s indulgence for my argument.
I’ll start by defining what a soul is, if there are different types of souls, and if some or all souls are immortal. I will then continue to show that the attributes attributed to immortal or spiritual souls exist in non-human animals.
A note on language. I will use the term “non-human animals” to refer to species that are not human. Strictly speaking, human beings belong to the genus of animals.
Body and soul
The Catechism of the Catholic Church gives the most precise definition of the soul. “The spiritual principle of human beings. The soul is the subject of human conscience and freedom; soul and body together form one human nature. Each human soul is individual and immortal, immediately created by God. The soul does not die with the body, from which it is separated by death, and with which it will be reunited in the final resurrection..
While the body is composed of matter subject to decay (essentially, organs and tissues decay into simpler organic forms), the soul is an immaterial substance and, therefore, not subject to decay.
Types of Souls
Traditionally souls are classified as vegetative, sentient or rational (Thomas Aquinas, The Summa Theologica, Part I QQ LXXV.CII. Flight. 4).
The vegetative soul is only possessed by plants. The powers attributed to the vegetative soul are reproduction, nutrition and growth. Since these powers are reducible to the plant’s body or material function, the plant’s soul is not immortal.
The sentient soul possesses the powers of the vegetative soul and adds the capacity to receive and react to sense impressions. However, he lacks rational thinking ability. This is the type of soul possessed by non-human animals. The philosophical view is that while the sentient soul is an immaterial substance, it depends on the body for its existence and therefore is not immortal. It is this conclusion that I want to challenge and to which we will return later.
Finally, the rational soul possesses all the powers of the sensitive soul and adds to it the power of rational thought. While the term “rational thought” can incorporate several qualities, any definition should include the ability of free will, logic, speech, and levels of cognition. These traits manifest in the physical body through the brain, which itself acts on the mind.
The spirit is the soul made manifest in the body. There are several reasons to suggest this conclusion, perhaps none more compelling than the mystery of consciousness. The word itself is difficult to define and can be understood differently depending on the circumstances. Yet the term often includes self-awareness, thought, will, and sensation.
Consciousness as a product of the mind is not bound by material concerns. This is obvious because conscious states such as intentionality and thought are neither divisible nor composed of matter.
Assuming that the attributes attributed to sentience (i.e. free will, intentionality and cognition) are not reducible to the different parts of the physical body, we can deduce that these attributes are qualities of a spiritual soul.
I now conclude the first part of this presentation. I defined the soul as an immaterial substance and the body as a material substance subject to decomposition. I also looked at the soul types and the attributes associated with each soul type.
In the second part of this talk, I will discuss whether nonhuman animals possess the attributes of a rational (and, therefore, immortal) soul.