George Santayana
Some of this is clearly a product of its time - Eurocentric point of view notwithstanding, there is much here to appreciate.
"Viewed from within, each religious or national fanaticism stands for a good; but in its outward operation it produces and becomes an evil. It is possible, no doubt, that its agents are really so far apart in nature and ideals that, like men and mosquitoes, they can stand in physical relations only, and if they meet can meet only to poison or to crush one another. More probably, however, humanity in them is no merely nominal essence; it is definable ideally, as essences are defined, by a partially identical function and intent. In that case, by studying their own nature, they could rise above their mutual opposition, and feel that in their fanaticism they were taking too contracted a view of their own souls and were hardly doing justice to themselves when they did such great injustice to others."
"Fanaticism consists in redoubling your effort when you have forgotten your aim."
"Progress, far from consisting in change, depends on retentiveness. When change is absolute there remains no being to improve and no direction is set for possible improvement: and when experience is not retained, as among savages, infancy is perpetual. Those who cannot remember the past are condemned to repeat it. In the first stage of life the mind is frivolous and easily distracted; it misses progress by failing in consecutiveness and persistence. This is the condition of children and barbarians, in whom instinct has learned nothing from experience. In a second stage men are docile to events, plastic to new habits and suggestions, yet able to graft them on original instincts, which they thus bring to fuller satisfaction. This is the plane of manhood and true progress. Last comes a stage when retentiveness is exhausted and all that happens is at once forgotten; a vain, because unpractical, repetition of the past takes the place of plasticity and fertile readaptation. In a moving world readaptation is the price of longevity. The hard shell, far from protecting the vital principle, condemns it to die down slowly and be gradually chilled; immortality in such a case must have been secured earlier, by giving birth to a generation plastic to the contemporary world and able to retain its lessons. Thus old age is as forgetful as youth, and more incorrigible; it displays the same inattentiveness to conditions; its memory becomes self-repeating and degenerates into an instinctive reaction, like a bird's chirp."
- The Life of Reason