Roosevelt contrasts a life of purposeful risk with one organised around avoiding both failure and disappointment. To “dare mighty things” is to attempt difficult or consequential work despite the possibility of defeat. Success is valued, but the quotation does not make success the condition for worthwhile action: even triumphs that are “checkered by failure” are presented as preferable to never taking a meaningful risk.

The central quality is courage rather than ambition alone. Roosevelt’s argument is that accepting exposure to failure is part of acting boldly. The “gray twilight” represents a condition of safety achieved through disengagement, where a person experiences neither major victory nor major defeat. The quotation can therefore be read as a defence of participation, effort and calculated risk, particularly when fear of failure might otherwise lead to inaction.

Full quotation

“As it is with the individual, so it is with the nation. It is a base untruth to say that happy is the nation that has no history. Thrice happy is the nation that has a glorious history. Far better it is to dare mighty things, to win glorious triumphs, even though checkered by failure, than to take rank with those poor spirits who neither enjoy much nor suffer much, because they live in the gray twilight that knows not victory nor defeat. If, in 1861, the men who loved the Union had believed that peace was the end of all things, and war and strife the worst of all things, and had acted up to their belief, we would have saved hundreds of thousands of lives, we would have saved hundreds of millions of dollars. Moreover, besides saving all the blood and treasure we then lavished, we would have prevented the heartbreak of many women, the dissolution of many homes, and we would have spared the country those months of gloom and shame when it seemed as if our armies marched only to defeat. We could have avoided all this suffering simply by shrinking from strife. And if we had thus avoided it, we would have shown that we were weaklings, and that we were unfit to stand among the great nations of the earth. Thank God for the iron in the blood of our fathers, the men who upheld the wisdom of Lincoln, and bore sword or rifle in the armies of Grant! Let us, the children of the men who proved themselves equal to the mighty days, let us, the children of the men who carried the great Civil War to a triumphant conclusion, praise the God of our fathers that the ignoble counsels of peace were rejected; that the suffering and loss, the blackness of sorrow and despair, were unflinchingly faced, and the years of strife endured; for in the end the slave was freed, the Union restored, and the mighty American Republic placed once more as a helmeted queen among nations.”