But why was the Neapolitan endowed with perfect proportions? The answer built on the commonly accepted Galenic theory of four humours and its relationship to climate. Following tradition, Blundeville believed that the external proportions and the behavior of the horse reflected the internal proportions of the four bodily humours of blood, phlegm, and black and yellow bile. Every animal's body and character was determined by the particular humoural mix of these four fluids. In turn, it was the climate of a land that determined the humoural make-up of a creature. In hot and dry lands, creatures tended to have an overabundance of yellow bile. In wet and cold lands, like England, creatures tended to have too much phlegm and, as a result, had a rather phlegmatic character. Clearly, the land with the best, most moderate climate produced the best horses, and what could beat the balmy weather of the bay of Naples? That was the reason why the Neapolitan courser was perfect, beautiful, healthy, and strong, ready to withstand any adversity. As Blundeville wrote,