The sentence “A rose is a rose is a rose,” was written by Gertrude Stein as part of a poem. It has, in modern times, equated with the often interpreted meaning, “things are what they are.”
For another literary giant, Robert Frost, points out in his poem, The Rose Family, that while the world’s definition of beauty can change, true beauty is in the “eye of the beholder.”

The rose is a rose,
And was always a rose.
But the theory now goes
That the apple’s a rose,
And the pear is, and so’s
The plum, I suppose.
The dear only know
What will next prove a rose.
–Robert Frost