Does the Catholic Church teach that animals are mere “organic robots” without consciousness?… there is a difference between attributing consciousness to animals and attributing reason to them. While it is true that the Christian tradition denies that animals have reason (as did, generally, the Greek philosophical tradition before it—there is nothing distinctively Christian about the idea), it did not generally deny that animals are conscious, or in particular that they feel pain and have other sensations. Famously, Aristotelians, including Christian Aristotelians like St. Thomas Aquinas, distinguish between the animal soul and the rational soul, where the animal soul is the form of non-human animals and the rational soul is the form of human beings. The rational soul includes the powers of the animal soul, but not vice versa. So animals lack the power to reason. Still, the animal soul includes the power of sensation.
…what made Descartes’ conception of the nature of the human soul distinctive is that he assimilated consciousness and reason, so that anything that lacked reason necessarily also lacked consciousness (and thus sensation). He also conceived of the soul as a substance rather than a form. This went hand in hand with his endorsement of the modern mechanistic conception of matter, which rejects Aristotelian forms and final causes as playing any part in the explanation of a physical substance. The upshot of this is that animals just as much as any other physical system, including human bodies, lack forms in the Aristotelian sense and thus lack anything like Aristotle’s animal soul. But since they also lack language and thus the power of reason, we have every reason, given Descartes metaphysical picture, to conclude that their bodies are not associated, as human bodies are, with immaterial substances. Hence
they must be mere machines, as everything else in nature is that lacks an immaterial substance or Cartesian soul.
John Gray on Descartes and Animal Consciousness
The Hebrew, biblical term for all living organisms is “nephsh” (Gen. 1:21; Lev. 11:46; Gen. 2:7), though it is often translated by the term soul but it means a living organism and by extension, a life-giving principle, the whole personality in humans. Thus the Hebrew usage of the term technically means a “vital force” animating the living creatures, men and beasts that was imparted by the God’s breath, “ruach,” (Gen. 2:7; Ecclesiastes 3:19). It does not seem to have the divine nature, is not immortal …
… there is no term in Hebrew for the body. The term which is usually translated as the body is basar, “sarx” in Greek and in Latin caro. But basar means a whole man, the whole living being, human or animal, the body and the soul as one psychosomatic entity. In Aristotle it corresponds to the living body or syntheton.
THE PROBLEM OF THE SOUL IN ARISTOTLE’S De anima