The hand commonly is considered to have exerted great influence on the evolution of typically human characteristics, like upright posture, stereoscopic vision, -manipulative- handling of parts of the environment. The German term -Begreifen-, which is commonly used for the understanding of complex relationships in a generalised, abstract sense, always implies the original meaning of seizing objects with the aid of the hands. The hands are also of greatest importance for the survival of the other, non-human primates. Hands are absolutely essential for locomotion in an arboreal habitat, and the...