We have already seen how false is the theory that holds that there is always a sudden stroke of inspiration, followed by a period of rapid or slow execution. On the contrary, observation reveals many processes that apparently differ less in the _content_ of invention than according to individual temperament. I distinguish two general processes of which the rest are variations. In all creation, great or small, there is a directing idea, an "ideal"--understanding the word not in its transcendental sense, but merely as synonymous with end or goal--or more simply, a problem to solve. The _locus_ of the idea, of the given problem, is not the same in the two processes. In the one I term "complete" the ideal is at the beginning: in the "abridged" it is in the middle. There are also other differences which the following tables will make more clear: _First Process_ (_complete_). 1st phase 2nd phase 3d phase IDEA INVENTION, VERIFICATION, (commencement) or or Special incubation DISCOVERY APPLICATION of more or less (end) duration The idea excites attention and takes a fixed character. The period of brooding begins. For Newton it lasted seventeen years, and at the time of definitely establishing his discovery by calculation he was so overcome with emotion that he had to assign to another the task of completing it. The mathematician Hamilton tells us that his method of quaternians burst upon him one day, completely finished, while he was near a bridge in Dublin. "In that moment I had the result of fifteen years' labor." Darwin gathers material during his voyages, spends a long time observing plants and animals, then through the chance reading of Malthus' book, hits upon and formulates his theory. In literary and artistic creation similar examples are frequent.[72] The second phase is only an instant, but essential--the moment of discovery, when the creator exclaims his "Eureka!"[73] With it, the work is virtually or really ended. _Second Process_ (_abridged_). 1st phase 2nd phase 3rd phase General preparation IDEA (commencement) CONSTRUCTIVE (unconscious) INSPIRATION and ERUPTION DEVELOPING period. This is the process in intuitive minds. Such seems to have been the case of Mozart, Poe, etc. Without attempting what would be a tedious enumeration of examples, we may say that this form of creation comprises two classes--those coming to maturity through an internal impulse, a sudden stroke of inspiration, and those who are suddenly illumined by chance. The two processes differ superficially rather than essentially. Let us briefly compare them.