Human spirit also differs from animal spirit in many respects...

Human spirit also differs from animal spirit in many respects; including the human capacity to communicate by employing letters, words, thoughts, etc., and the human psychological variations—such as laughter, weeping, etc.—in response to different external phenomena. The existence of art, industry, and human innovation display clearly the superiority of the human soul as they have no place in the realm of animals.

The essential difference of the human soul from the animal soul is that the former is intellectual while the latter is imaginal. In addition, the sole pursuit of the animal soul is the gratification of the corporeal needs while the scope of human soul, in terms of its conceptual and practical aspects, stretches to the farthest reaches of existence.

Detailed Answer The Existence of Spirit in Animals The Animal Soul as One of the Instances of Spirit in Existence In philosophical inquiries into the topic of the soul, where the soul is defined, it is commonly divided into three classes: vegetable soul, animal soul, and human soul. Despite the fact that each one of these classes possesses its own peculiarities which distinguish it from its counterparts, they all share a common reality and essence.

The soul is a spiritual and immaterial existent which incorporates spiritual faculties, whether it be the intellectual soul, the imaginal soul[^1], or the vegetable soul. The Creation of the Animal Spirit as One of the Phases of the Origination of the Realm of Materiality Mulla Sadra is among those thinkers who hold that the origination of material existents was carried out in stages, starting from the simplest and advancing to the stage of the most perfect elements.

In some of these stages, the mere combination of material ingredients was not enough and thus the addition of an immaterial element to the composition was called for, so as to satisfy the requirements of that particular order of creation. One such stage was the creation of the animal. The spirit that was infused in the composition to bring about the animal existence is termed the “animal spirit”. Hence, not only does the animal possess a soul, furthermore it owes its essence to that soul.

The addition of the soul to the material ingredients is a requirement of the order of the realm of materiality. And the same case applies to the realms of the human being and the vegetable. The immaterial spirit or soul is what distinguishes some material entities from others.