We need to be bold and adventurous in our thinking in order to survive.

A man may die, nations may rise and fall, but an idea lives on. Ideas have endurance without death.

Those who are fired with an enthusiastic idea and who allow it to take hold and dominate their thoughts find that new worlds open for them. As long as enthusiasm holds out, so will new opportunities.

Some ideas are born as you write then down, others become dead.

Do not stop thinking of life as an adventure. You have no security unless you can live bravely, excitingly, imaginatively; unless you can choose a challenge instead of competence.

I say to the young: Do not stop thinking of life as an adventure. You have no security unless you can live bravely, excitingly, imaginatively.

Ideas, unlike solid structures, do not perish. They remain immortal, immaterial and everywhere, like all Divine things. Ideas are a golden, savage landscape that we wander unaware, without a map. Be careful: in the last analysis, reality may be exactly what we think it is.

Thought is an Idea in transit, which when once released, never can be lured back, nor the spoken word recalled. Nor ever can the overt act be erased.

Ideals survive through change. They die through inertia in the face of challenge.

Still I can't get it out of my mind what a discrepancy there is between ideas and living. A permanent dislocation, though we try to cover the two with a bright awning. And it won't go. Ideas have to be wedded to action; if there is no sex, no vitality in them, there is no action. Ideas cannot exist alone in the vacuum of the mind. Ideas are related to living: liver ideas, kidney ideas, interstitial ideas, etc. If it were only for the sake of an idea Copernicus would have smashed the existent macrocosm and Columbus would have foundered in the Sargasso Sea. The aesthetics of the idea breeds flowerpots and flowerpots you put on the window sill. But if there be no rain or sun of what use putting flowerpots outside the window?

Todos tenemos ideas. Las ideas son inmortales. Duran siempre. Lo que no dura siempre es la inspiración. Es como la fruta fresca o la leche: tiene fecha de caducidad. Si quieres hacer algo, tienes que hacerlo ahora.

For me, the adventures of the mind, each inflection of thought, each movement, nuance, growth, discovery, is a source of exhilaration.

Ideas won't keep. Something must be done about them.

Ideas won't keep; something must be done about them.