Just like ideals, goals cannot be ever achieved. They are meant to be a puller to get someone to move in the right way, in the right direction.
Nothing is pure in this world, unlike ideals and perfect goals, no one is purely savagery, nor purely a reasonable saint. All have got some mixture of either in them. In every most extreme savages we can fnd, there would be slight traces of reason for them. And for the most high virtue angel-like, a bit of savagery nature is surely to be found. We see the samething with substances too. Not one single substance in this world comes in perfectness. Is there a chunk of gold ore that's 98% above gold? And neither can there be a pure, a absolutely pure gold ingot that's fully gold, perfect and flawless pure-pure gold with absolutely no traces of other substances. For very matter there is, there must be a non-zero inpurity, thus making all things inpure, in a way. However, like the paradox of nature it is, some things just might be considerable as "pure enough". The elements themselves too follow the general rule of inpureness, for the lack of a better term there. Many have one if not more isotopes. Water, something supposedly pure and feels like has nothing but its own cannot be found in its most "perfect" form. After filteration there would still be some left. And with super technology from fantasy future world, the isolation of isotopes of hydrogen oxide would still be a major task to overcome, and a great achievement to accomplish.
The two extremes of a spectrum, the very two extremes that is, would be ones of pure 100% this or 100% that. And we could not find such beings in nature. Most extreme cases would be someone of inpure composition still: 98% this, with 2% that. Everyone seem to fall in between that line, and no one reside on the extreme ends of the spectrum - always in between. Is it physically impossible to reach those ends? Or is it because it's not meant to be? Though seems we can belief whichever and imagine whatever we want to, physical constraint nevertheless keeps things out of reality, or in reality. Fantasies will forever be fantasies, however, somehow they guide our souls, and directions, and seem to have more of a pull on us than gravity. Ideals can be pure in form, however no such similar-in-nature things can be found in life. So is it not saying directly to us then by that that no goals should be achieved, neither should any ideals be really persuaded for? =]
