The unforgivable sin is the refusal to pardon.

It takes a wonderful brain and exquisite senses to produce a few stupid ideas.

Progress, far from consisting in change, depends on retentiveness. Those who cannot remember the past are condemned to repeat it.

Memory itself is an internal rumour; and when to this hearsay within the mind we add the falsified echoes that reach us from others, we have but a shifting and unseizable basis to build upon. The picture we frame of the past changes continually and grows every day less similar to the original experience which it purports to describe.

Old places and old persons in their turn, when spirit dwells in them, have an intrinsic vitality of which youth is incapable, precisely, the balance and wisdom that come from long perspectives and broad foundations

History is always written wrong, and so always needs to be rewritten. ...What is interesting is brought forward as if it had been central and efficacious in the march of events, and harmonies are turned into causes. Kings and generals are endowed with motives appropriate to what the historian values in their actions; plans are imputed to them prophetic of their actual achievements, while the thoughts that really preoccupied them remain buried in absolute oblivion.

You cannot prove realism to a complete sceptic or idealist; but you can show an honest man that he is not a complete sceptic or idealist, but a realist at heart. So long as he is alive his sincere philosophy must fulfil the assumptions of his life and not destroy him.