The mereological problem known as the paradox of the heap raises fundamental questions about the nature of composition and emergence. This article reformulates the paradox in terms of neuroscience, arguing that if a single neuron does not constitute a brain and the incremental addition of neurons does not, in itself, create a brain, then no collection of neurons should ever form a brain. This contradicts empirical reality. To address this issue, I propose a new conceptual framework—mereological emergentism—where existence is marked by the emergence of novel properties. This framework posits that a whole begins to exist as soon as its components collectively generate new properties, offering a linguistic and meta-ontological perspective on composition. Through this approach, I illustrate how mereological emergentism provides a coherent resolution to the paradox and a useful perspective for theoretical studies.