Freedom is that faculty that enlarges the usefulness of all other faculties.

Every man is to be respected as an absolute end in himself; and it is a crime against the dignity that belongs to him as a human being, to use him as a mere means for some external purpose.

Thrift is care and scruple in the spending of one's means. It is not a virtue and it requires neither skill nor talent.

Enthusiasm is always connected with the senses, whatever be the object that excites it. The true strength of virtue is serenity of mind, combined with a deliberate and steadfast determination to execute her laws. That is the healthful condition of the moral life; on the other hand, enthusiasm, even when excited by representations of goodness, is a brilliant but feverish glow which leaves only exhaustion and languor behind.

Morality is not properly the doctrine of how we may make ourselves happy, but how we may make ourselves worthy of happiness.

Experience without theory is blind, but theory without experience is mere intellectual play.

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.