He suspected it might be a law of Erfworld, but there was not enough evidence.
Strengths: Curiosity, Generosity, Inventiveness, Building Scientific Instruments, Stylish Jackets
Weaknesses: Loneliness, Focus, Courage of Convictions
First Appearance: TBFGK 140
First seen when Parson entered the Magic Kingdom after the Battle for Gobwin Knob, he summoned the Thinkamancers to unravel the Croakamancer-Dirtamancer link up, saying they'd do it for no charge.
Isaac is a rarity among the casters of the Magic Kingdom, not content with debating and arguing over theories and hypotheses on the nature of magic and Erf, but actively working to discern reliable and consistent facts. So far, this has led to the creation of a number of devices to aid thinkamancers in better accessing nodes of amplification or attuning to the frequencies of certain G-String vibrations (all of which resemble children's playground equipment from our world).
Should he ever link up with a Carnymancer, they will create devices capable of automatically switching Thinkamancers between nodes at precisely calibrated frequencies to achieve Thinkamancy that, while not as versatile, will actually rival the Arkendish in power (like a Ferris Wheel or a Roller Coaster).
Isaac may hope that he or one of the other Great Minds that Think Alike can replace Charlie as the attuned holder of the Arkendish, if Parson succeeds in defeating Charlie. This would explain their motivation and Janis' comment about the Thinkamancers "thinking" they understood the purpose of summoning the "Perfect Warlord".
Real World References
His name coupled with his tendencies as a natural philosopher are a reference to Isaac Newton.
His appearance is a reference to Carl Sagan.
His desire for the Arkendish as a tool of observation may also be a reference the use of radio telescopes in astronomy.
Both Carl Sagan and Isaac Newton were teachers, and one of the titles for the person in charge of a school is Headmaster.