“It may be a distasteful notion, this bringing down of happiness so low as to the animal world—making it over, as then we must, even to the vilest of them and not withholding it even from the plants, living they too and having a life unfolding to a term.
“But to begin with, it is surely unsound to deny that good of life to animals only because they do not appear to man to be of great account. And as for plants, we need not necessarily allow to them what we accord to the other forms of life, since they have no feeling. It is true people might be found to declare prosperity possibly to the very plants; they have life, and life may bring good or evil; …
“Those that deny the happy life to the plants on the ground that they lack sensation are really denying it to all living things.” ~Plotinus
Plotinus wrote this around 1,800 years ago so he was not familiar with recent research which indicates that plants react when they are injured, or other plants or animals are killed or injured. Although some more recent research came to a different conclusion, one experiment doesn’t necessarily cancel out the other one, especially when the latter ones were conducted by a TV show with an obvious prejudice as they are called Myth Busters. More experiments are needed that are done by neutral parties. I do know that some wine producers play music for the vines to get better tasting wine and a Tequila maker I visited this spring in Mexico plays music to mellow the aging mix while it is in a tank.
But I think the point that Plotinus is really trying to make is not that plants are, to some degree, sentient beings also, but rather that all life is essentially the same, it just takes different forms and the form is not life. If humans have a right to happiness, as we are guaranteed the right to pursue in the United States Declaration of Independence, than we must grant the same right to all life. If we are greedy and say that happiness is for humans only, then we should not be surprised when other living things deny our happiness in favor of their own.
Plotinus admits that the definition of what happiness is may be different for humans, animals, and plants, yet each has a right to that happiness. It is a great step forward that in many cases people now consider what harm may be done to animals before they do things like drain a lake or a swamp or plow down hundreds of acres of trees to build more houses for humans whiles dozens of ghost towns sit abandoned instead of being rebuilt and reused, but we need to do it more and to consider the plants as well. And then maybe we can get over the idea that it’s OK to blast huge holes in the Earth itself to take out gems, crystals and metals.
A spiritual person understands this because she knows that spirits are all the same regardless of the physical mask they are wearing at the present time. And true happiness is a free and aware spirit and soul that is not interested at all in struggling with other physical life forms to keep itself alive a little longer because the awakened spirit and soul is well aware that it is immortal.