This same philosophy is a good horse in the stable, but an arrant jade on a journey.

Goldsmith contrasts armchair “philosophy” with lived experience. A “good horse in the stable” suggests ideas that look sound when tested only in theory or in comfortable circumstances; the same horse becomes “an arrant jade on a journey” when real conditions—fatigue, uncertainty, hardship—demand practical endurance. The line satirizes moralizing and abstract systems that promise guidance but fail under pressure, a recurring concern in Goldsmith’s writing, which often favors humane observation over pedantic doctrine. It implies that wisdom must be judged by how it performs in the world, not by how elegantly it is stated.