It is common to see many chemists having a misconception that activation free energy cannot depend on thermodynamic driving force. At the same time, the Bell-Evans-Polanyi (BEP) principle, which describes a linear correlation of reaction rate constants (or other activation parameters within the same family of reactions) with reaction free energy, is also well recognized. This principle relates qualitatively to the Hammond postulate, which posits that thermodynamics does affect activation free energy. A possible reason for this paradoxical observation could be a very common logical fallacy, affirming the consequent. In textbooks, we learn that "a catalyst that changes the rate constant does not change the equilibrium constant, as catalysts accelerate both the forward and the backward reactions to the same extent." Affirming the consequent then arrives at the conclusion that the reverse, that thermodynamics does not change kinetics, must also be true.