Aldean The Aldeans were a civilization native to Aldea , which was considered only a legend for thousands of year s . The society was self - contained and self - sustaining with incredible technical sophistication providing daily needs . Similar to cultural myths of Neinman on Xerxes VII or the Earth story of Atlantis , Aldea was said to have shed its past of violence and cultural conflict and evolved to a pure state , devoting themselves to culture and art . The Aldean culture developed by emphasizing the fundamental principle that for " everything taken , something must be returned . " It was this principle that allowed their civilization to ascend to incredible heights in technology and art . Having reached enlightenment , hundreds of centuries ago , the Aldean society retreated from the rest of the galaxy . To facilitate this , their progenitor s built an enormous and advanced planet - wide defense system . The system , run by the computer called the Custodian , maintained an immense cloaking device and defense shield , in addition to a repulsor beam powerful enough to push starship s several hundred light year s away . However , the long - term effects of the planet ' s defenses were extremely damaging . Millennia after the Aldeans retreated behind their cloak , cumulative wide - spread environmental damage , including depletion of their ozone layer , began to take their toll . The Aldeans suffered from long - term chromosomal damage from radiation poisoning due to exposure to their sun ' s ultraviolet rays . By 2364 , the entire population of Aldea was infertile and depleted . No child had been born on Aldea for more than thirty years , and most of native wildlife on the planet , including all the fish in their ocean s , had long ago become extinct . Desperate to preserve their society as it would likely become extinct alongside themselves , the Aldeans , led by Radue contacted the for help in repopulating their planet . Unable to reproduce themselves , the Aldeans offered to exchange their vast knowledge for a select few of the " Enterprise " - D ' s children . The Aldeans were physiologically very similar to Human s , which presumably was a deciding factor when they contacted the " Enterprise " - D . The " Enterprise " - D turned down the offer , leading the Aldeans to kidnap the children , creating a stand - off that was eventually resolved when Doctor Beverly Crusher proved that the very thing which had protected Aldea , its cloak , was responsible for their condition . Fortunately , Federation medicine would be able to reverse it and make the species fertile again . The Aldeans returned the children and set about re - learning their own technology and adjusting to a new galaxy where they were no longer just a legend . Aldean society was structured into unit s , or social groups , which specialized in a particular art or pursuit such as medicine or science . Within each group student s were fully devoted to their discipline . The Aldeans had perfected their system of education and study to the point where the natural abilities of the individual blossomed very quickly , sometimes within hour s or day s of the student ' s first exposure to a medium . ( )