G‑d created man with a unique nature, different not only from the nature of terrestrial and celestial hosts, but also from the nature of the supernal sefirot. All these beings possess a single nature, this nature constituting what they are. Terrestrial creatures have coarse corporeal bodies and are capable of acting in accordance with their one emotive character in a single way, whether through kindness or mercy, or severity and cruelty. Celestial hosts have bodies as well, though their bodies are composed of a subtle substance; therefore, they too can act only in a single mode, except that their actions have several beneficial properties.
Man … is comprised of both the essential advantages of the supernal creatures and the baseness of the lower earthly creatures….
The action of the sun, for example, is to illuminate. Its beneficial properties are that it heals, improves the growth of vegetation, ripens fruit and crops, and so on. The supernal creatures - including both the angels, which are divisible into ten categories, as explained by Maimonides (Hilchot Yesodei Hatorah 2:7), and the ten sefirot, from chochma to malchut - all perform singular actions.
Man, however, is different. He is comprised of both the essential advantages of the supernal creatures and the baseness of the lower earthly creatures, and his actions are many and diverse.
Man, by nature, is grafted from numerous different attributes that oppose each other. In the words of Maimonides (Commentary to Mishna, Intro.), "All living creatures and trees have only one function, or two functions…Man, however, can perform many actions that vary from one another." (Likutei Torah, Emor 37c).
Some actions stem from man's body, and others, from his soul….
This capacity of man - implanted in him by G‑d - to act in many diverse ways is in harmony with both the composition of his body and the propensities of his soul. Although terrestrial and celestial creatures possess different types of bodies - the bodies of the former are composed of coarse material, the bodies of the latter are composed of ethereal matter - nevertheless, the actions of both types of creatures stem from [and are attributable to] their respective bodies. The actions of the supernal sefirot, on the other hand, stem from [and are attributable to] their souls. Man, who possesses elements of both the supernal and the non-supernal, acts in a dual manner. Some actions stem from man's body, and others, from his soul.
Among the various traits G‑d infused in man is not only the capacity to influence and to affect that which is external to him, but also the susceptibility to be himself influenced and affected by that which is outside of him. For example, man is affected by his food: to refine his understanding and intellect, he must eat refined foods. Similarly, [he should dress with care since donning] fine clothing broadens mental perceptiveness. [Man is likewise influenced by his surroundings. To illustrate:] Those who dwell in small towns enjoy longer life.
[Adapted by Y. Eliezer Danziger from The Principles of Education and Guidance (Kehot), pp. 64-66.]