Logician/ləˈdʒɪʃn/ Definition 1 of 2Pro Tip 1/3Problem Solver Highlighting logician's role in finding solutions to difficult puzzles or problems. The logician devised an algorithm to decrypt the encoded message. Pro Tip 2/3Not Always Math Logicians don't only work with numbers, they apply logic to many fields. As a logician, she contributed to the field of computer science. Pro Tip 3/3Critical Thinking A logician's skill is based on reasoning and evaluating arguments critically. The logician explained why the argument was flawed.