From the #AngelicDoctor...
"It is common to every nature to have some inclination; and this is its natural appetite or love. This inclination is found to exist differently in different natures; but in each according to its mode. Consequently, in the intellectual nature [humans] there is to be found a natural inclination coming from the will; in the sensitive nature [animals], according to the sensitive appetite; but in a nature devoid of knowledge, only according to the tendency of the nature to something."
-- #SaintThomasAquinas (1225-74)