The greatest achievement of humanity is the human spirit.

Strength is not measured by physical prowess alone, but by the resilience and determination of the human spirit.

Nothing can contain the limitless spirit of a boundless heart.

Here in this region beyond thought the human spirit actively soars.

The human spirit will not invest itself in a compromise.

There should be no boundary to human endeavor.

The single idea that resounds on every page of this book is the idea of the infinity of the human spirit, in the individual as well as in humanity. It is a view of the wonderful and terrible disproportion of that spirit to everything that would contain and diminish it, of its awakening to its own nature through its confrontation with the reality of constraint and the prospect of death, of its terror before the indifference and vastness of the nature around it, of its discovery that what it most shares with the whole of the universe is its ruination by time, of its subsequent recognition that time is the core of reality if anything is, of its enslavement to orders of society and culture that belittle it, of its need to create a world, a human world, in which it can be and become itself even if to do so it must nevertheless rebel against every dogma, every custom, and every empire, and of its power to realize this seemingly impossible and paradoxical program by identifying, in each intellectual and political situation, the next steps.

El espíritu humano es muy, muy poderoso. Él sabe que puede lograr cualquier cosa.

How amazing is the spirit of man!...it is impossible to lose hope for him. In the midst of disaster he has not lost his dignity or his faith in the values he cherished. Plaything of nature's mighty forces, less than a speck of dust in this vast universe, he has hurled defiance at the elemental powers, and with his mind, cradle of revolution, sought to master them. Whatever gods there may be, there is something godlike in man, as there is something of the devil in him.
The future is dark, uncertain. But we can see part of the way leading to it and can tread it with firm steps, remembering that nothing that can happen is likely to overcome the spirit of man which has survived many perils. Remembering also that life, for all its ills, has joy and beauty, and we can always wander,if we know how to, in the enchanted woods of nature.

There are no constraints on the human mind, no walls around the human spirit, no barriers to our progress except those we ourselves erect.

There should be no boundaries to human endeavor. (...) However bad life may seem (...) While there’s life, there is hope.

In all these ways, and through all these years, there has been made manifest the unconquered and unconquerable spirit of our race, nourished on the glorious traditions of many centuries of freedom. This spirit, conscious of its strength, bore the trials and disappointments of these years with a fortitude that was never shaken and a confidence that never failed. It knew its motives to be pure, and it held fast to its faith that Divine Providence would not suffer injustice and oppression to prevail.

The inner life has no boundaries

No matter how long a wall has stood, none has the power to withstand the continued force of human beings who have decided to persist until it has fallen. The human spirit truly is unconquerable.