Source: The Critic as Artist (1891), an essay by Oscar Wilde

Complete Sentence: Gilbert. The one duty we owe to history is to re-write it. That is not the least of the tasks in store for the critical spirit. When we have fully discovered the scientific laws that govern life, we shall realise that the one person who has more illusions than the dreamer is the man of action. He, indeed, knows neither the origin of his deeds nor their results. From the field in which he thought that he had sown thorns, we have gathered our vintage, and the fig-tree that he planted for our pleasure is as barren as the thistle, and more bitter. It is because Humanity has never known where it was going that it has been able to find its way.