Q: Why doesn’t man receive this knowledge naturally, like animals?
A: It’s true that animals know how to sustain themselves correctly and naturally. They receive this information as instincts, because they all exist in a certain and fixed level of development, as it says, “A day old calf is called an ox.” This is all they need.
The developing man, however, does not receive the inborn attributes of animals naturally. That difference is so apparent, that it is amazing to see the difference between the correct and meaningful movements of a calf, and those of a human infant. You can read more about it in the essay: "The Essence of Religion and Its Purpose".