143. These days it may seem strange that in ancient times animals and beasts symbolized feelings and similar human qualities. But [in the first place] people then viewed things the way heaven does, and [in the second place] animals represent these qualities in the world of spirits as well. (In fact a quality is represented by an animal whose nature reflects that quality.) In consequence, when the ancients mentioned the animals they meant nothing else than the qualities.
In the Word, too, no other meaning is intended in any passage that mentions animals in general or in particular. The whole of the prophetic portion is full of these references. Not knowing what each species of animal symbolizes makes it impossible to understand what the Word contains in its inner meaning.
As noted above [§45], animals are of two kinds: bad (because they are dangerous) and good (because they are harmless). The good ones, such as sheep, lambs, and doves, symbolize positive emotions. Here, where the heavenly person (or the heavenly kind of spiritual person) is the subject, that is their symbolism.
Sections 45, 46 quoted several places in the Word that show that animals in general symbolize feelings, eliminating the need for further demonstration here.