The first law of ecology is that title above, at least as written in Barry Commoner's 1971  The Closing Circle:  Nature, Man and Technology .   A  further searc h indicated that the adage is attributed to Leonardo da Vinci, who died in 1519.  But there is very little to support this contention. From German  philosopher Gotthold Ephraim Lessing in 1769: In nature everything is connected, everything is interwoven, everything changes with everything, everything merges from one into another . Close, but what about U.S. jurist Oliver Wendell Holmes Jr., who wrote: If the world is a subject for rational thought it is all of one piece; the same laws are found everywhere, and   everything is connected with everything else;   and if this is so, there is nothing mean, and nothing in which may not be seen the universal law. And there is an environmental inspiration from U.S. naturalist John Muir in 1869: When we try to pick out anything by itself, we find it hitched to everything else in the