There was no concept of intellectual property in the ancient world, and plagiarism was widely seen as a homage to the original author. The Stanford Encyclopedia claims "It must also be recognized that 'forgery' is a modern notion. Like Plotinus and the Cappadocian Fathers before him, Dionysius does not claim to be an innovator, but rather a communicator of a tradition." However, while the Pseudo Dionysius can be seen as a communicator of tradition, he can also be seen as a polemicist, who tried to alter Neo-Platonic tradition in a novel way for the Christian world that would make notions of complicated Divine Hierarchies more of an emphasis than notions of direct relationship with the figure of Christ as Mediator.
Yes, there was no concept of intellectual property in the ancient world. None of the seers of the Upanishads ever claimed themselves to be its authors because they knew that they do not have metaphysical free will and everything was working according to the will of the Father.
"Just as the demiurge secretly moved by Sophia believes that he acts alone the same also with human beings."
- Excerpts of Theodotus
The Vedic seers knew that this body and this world belongs to God and surrendered their will to him without publishing their works in their names. It is the attitude of stupid scientists who cry out like silly school children when their works are plagiarized who think that this idea is theirs as though they have invented the idea all by themselves. The truth is there is no such thing as invention instead we only discover ideas which are already invented by God. Neither I am going to give attribution to others works nor I am going to ask attribution for my ideas.