Settle, for sure and universally, what conduct will promote the happiness of a rational being.
The whole interest of my reason, whether speculative or practical, is concentrated in the three following questions: What can I know? What should I do? What may I hope? (Critique of Pure Reason
Thoughts without content are empty, intuitions without concepts are blind.
Rules for happiness: something to do, someone to love, something to hope for.
Two things fill the mind with ever-increasing wonder and awe, the more often and the more intensely the mind of thought is drawn to them: the starry heavens above me and the moral law within me.
One who makes himself a worm cannot complain afterwards if people step on him.
In every department of physical science there is only so much science, properly so-called, as there is mathematics.
Live your life as though your every act were to become a universal law.
Enlightenment is man’s release from his self-incurred tutelage. Tutelage is man’s inability to make use of his understanding without direction from another. Self-incurred is this tutelage when its cause lies not in lack of reason but in lack of resolution and courage to use it without direction from another. Sapere aude! ‘Have courage to use your own reason!’- that is the motto of enlightenment.
Only the descent into the hell of self-knowledge can pave the way to godliness.
…When he puts a thing on a pedestal and calls it beautiful, he demands the same delight from others. He judges not merely for himself, but for all men, and then speaks of beauty as if it were the property of things.
Two things fill the mind with ever new and increasing admiration and awe, the more often and steadily we reflect upon them: the starry heavens above me and the moral law within me. I do not seek or conjecture either of them as if they were veiled obscurities or extravagances beyond the horizon of my vision; I see them before me and connect them immediately with the consciousness of my existence.
Act only according to that maxim whereby you can at the same time will that it should become a universal law.
Without man and his potential for moral progress, the whole of reality would be a mere wilderness, a thing in vain, and have no final purpose.