Enlightenment is man's emergence from his self-imposed immaturity...No thing is required for this enlightenment.. .except freedom; and the freedom in question is the least harmful of all, namely, the freedom to use reason publicly in all matters.
...as soon as we examine suicide from the standpoint of religion we immediately see it in its true light. We have been placed in this world under certain conditions and for specific purposes. But a suicide opposes the purpose of his creator; he arrives in the other world as one who has deserted his post; he must be looked upon as a rebel against God. God is our owner; we are his property; his providence works for our good.
Natural science physics contains in itself synthetical judgments a priori, as principles. ... Space then is a necessary representation a priori, which serves for the foundation of all external intuitions.
The schematicism by which our understanding deals with the phenomenal world ... is a skill so deeply hidden in the human soul that we shall hardly guess the secret trick that Nature here employs.
Christianity possesses the great advantage over Judaism of being represented as coming from the mouth of the first Teacher not as a statutory but as a moral religion, and as thus entering into the closest relation with reason so that, through reason, it was able of itself, without historical learning, to be spread at all times and among all peoples with the greatest trustworthiness.
The desire which a man has for a woman is not directed towards her because she is a human being, but because she is a woman ; that she is a human being is of no concern to the man; only her sex is the object of his desires.
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 and the moral law within.
A philosophical attempt to work out a universal history according to a natural plan directed to achieving the civic union of the human race must be regarded as possible and, indeed, as contributing to this end of Nature.