Hello friend,
this is an old idea. The theoretical premises are these:
a) The wheel symbolizes the [stupid] desire for the material world, as you can read on the Consolation of Philosophy of Boethius.
b) From a Christian perspective, the important thing is the desire of God, not the desire of material things.
c) The humans are not beast because the humans can have religion. Then if you are not religious, you're an animal.
For example, in the Consolation of Philosophy of Boethius (translated with Google translator):
Who has been transformed by evil can not be taken by men. Which has become a thief, his heart burns with greedy desires the good of others. We would say that is a wolf. The thug and bully with his tongue up countless lawsuits, we could compare it to a stray dog. The cunning trickster who hides in the ambush of their fraud will compare the fox. Al intemperate roaring with anger, we attribute the lion's heart. The fugitive trembling coward, terrified of imaginary fear, it seems the deer. The man slave softness and stupidity lives like donkeys. The weak and inconsistent constantly changing tastes no different from the birds. The passions that are wallowing in lewd lives trapped by the pleasure of disgusting pig. Happens, then that leaves virtue ceases to be man and, unable to be god, descends to the condition of the beast
In spanish:
«Quien se ha dejado transformar por el mal no puede ser tenido por hombre. Al que se ha hecho ladrón, el corazón le arde en codiciosos deseos del bien ajeno. Diríamos que es un lobo. El matón y pendenciero que con su lengua levanta pleitos sin cuento, podríamos compararlo con un perro callejero. Al astuto tramposo que se oculta en la emboscada de sus fraudes le compararemos al zorro. Al intemperante que ruge con ira, le atribuiremos el corazón de león. El cobarde tembloroso y fugitivo, aterrado por un miedo imaginario, se parece al ciervo. El hombre esclavo de la molicie y estupidez vive como los asnos. El débil e inconstante que cambia incesantemente de gustos no se diferencia de los pájaros. El que está enfangado en pasiones lascivas vive atrapado por el placer del cerdo repugnante. Sucede, entonces, que abandona la virtud, deja de ser hombre e, incapaz de ser dios, desciende a la condición de la bestia».
This idea was very strong in the Renaissance. For example, Vincenzo Cartari explained at the start of L' Imagini de i dei antichi (translated with Google translator):
«Of all the perfections of human nature, no more no more man's own religion, which is why there was never any people who did not participate in it somehow. Although it is said that man differs from beasts above all by reason, not least also noted that before using it, religion is showing it as something that comes natural to the human soul, as he explained the Platonic philosopher Iamblichus, which said that some divine light was coming to hurt our souls and awakened in them a natural appetite for good, on which we reflect later».
In italian:
«Di tutte le perfettioni date alla natura humana altra non è che sia maggiore della religione, ne piu propia all’huomo, e perciò non fu gente alcuna mai che di questa non participase in qualche modo. E benche si dica che la ragione principalmente fa l’huomo differente da gli animali bruti, nondimeno si vede che ancho innanzi à l’uso di questa , la religione si mostra in lui, come che naturalmente accompagni l’animo humano, secondo che diceva Iamblico Filosofo Platonico, il quale vuole che certo lume divino venghi à ferire gli animi nostri, e che in questi risvegli un appetitio naturale di bene, sopra del quale si discorre poi, e se ne fa giudicio».
Another example is the book La Circe of Giovanni Battista Gelli:
http://books.google.es/books?pg=PA7&dq= ... li&f=false