 Building Abstractions with Procedures e acts of the mind, wherein it exerts its power over simple ideas, are chiefly these three: 1. Combining several simple ideas into one compound one, and thus all complex ideas are made. 2. e second is bringing two ideas, whether sim- ple or complex, together, and seing them by one another so as to take a view of them at once, without uniting them into one, by which it gets all its ideas of relations. 3. e third is separating them from all other ideas that accom- pany them in their real existence: this is called abstraction, and thus all its general ideas are made. —John Locke, An Essay Concerning Human Understanding (1690) Wputational      the idea of a computational process. Com- processes are abstract beings that inhabit computers. As they evolve, processes manipulate other abstract things called data. 1