Everything built up from atomic distinctions
We affirm or postulate that all conceptual form emerges from the continuum by a process of motivated distinction, and we say this is true for the emergence of alphabets and written language.
We are building a "grand cascade" across levels.
And these levels are in a complex multi-type relationship.
Pure symbolic structure interacts with intuitive meaning and visualization and other sensory dimensionality.
This is a complex subject, and it is true in different ways at many levels. But it is an abstraction, an idealization.
In cognitive psychology, some of these "atomic" distinctions might be quite holistic, or gestalt-based. We see a "tree" as a whole, but we can also look at the parts of a tree and see them as units, and we can look at how these units are distinguished -- how their boundaries are defined, how their properties are assigned.
"Assigned" in an abstract model, "perceived" in direct experience.
Of course language has other levels -- such as sound, or visual imagery. See Susan Carey on the Origin of Concepts for powerful statements on this and the complex interaction between levels of analysis.