Immanuel Kant quotes
We are not rich by what we possess but by what we can do without. 
Always recognize that human individuals are ends, and do not use them as means to your end. 
Act in such a way that you treat humanity, whether in your own person or in the person of any other, never merely as a means to an end, but always at the same time as an end. 
Two things fill the mind with ever new and increasing admiration and awe, the oftener and more steadily we reflect on them: the starry heavens above me and the moral law within me.