A secular example to try to illustrate predeterminism is that a fetus's future physical, emotional, and other personal characteristics as a matured human being may be considered "predetermined" by heredity, i.e. derived from a chain of events going back long before her eventual birth. However, one of the difficulties with defining predeterminism using this example is that the word "predetermine" necessarily implies a conscious being "doing" the determining ahead of time. With regards to predetermined heredity, a conscious being (perhaps a genetic scientist) is presumed to be the one speculating on what the fetus's personal characteristics will turn out to be, for example, based on looking at the genomes of the fetus and its ancestors. If there were not this conscious entity, the scientist, then one could say merely that the fetus's characteristics are "determined" by heredity, rather than "pre"determined. Predeterminism necessarily implies, at the very least, a passive but all-knowing observer, if not an active planner, designer, or manipulator (of the fetus's personal characteristics). This basic scientific idea of hereditary determination, though, already fulfills the definition of causal determinism, a metaphysical concept.