tree of life stood also in the midst of the garden of eden (gen. 2:9; 3:22). some writers have advanced the opinion that this tree had some secret virtue, which was fitted to preserve life. probably the lesson conveyed was that life was to be sought by man, not in himself or in his own power, but from without, from him who is emphatically the life (john 1:4; 14:6). wisdom is compared to the tree of life (prov. 3:18). the "tree of life" spoken of in the book of revelation (rev. 2:7; 22:2, 14) is an emblem of the joys of the celestial paradise. tree of life (bot.), a tree of the genus thuja; arbor vit?... see tree
The concept of a tree of life is a widespread mytheme or archetype in the world's mythologies, related to the concept of sacred tree more generally, and hence in religious and philosophical tradition.
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Pak Breeders and Pak Protectors are two developmental stages of fictional life in Larry Niven's Known Space universe. The Pak first appeared in "The Adults," which appeared in Galaxy in 1967; this story was expanded into the novel Protector by Larry Niven (1973). The Pak also appear in several of Niven's later novels, notably those set in the Ringworld.