The major concepts, critiques and thinkers of deontology, a word that derives “from the Greek words for duty (deon) and science (or study) of (logos).”
This compact introduction offers an illuminating discussion of German philosophy, presenting it as one of the most revealing responses to the problems of "modernity." (Publisher's description)
This Very Short Introduction discusses the ideas and approaches of philosophers such as Kant, Hegel, Nietzsche, Husserl, Heidegger, Sartre, Habermas, Foucault, and Derrida, and introduces key concepts such as existentialism, nihilism, and phenomenology by explaining their place in the Continental tradition. (Publisher's description)
Stanford Encyclopedia of Philosophy
Further Reading
German Philosophy by 
Continental Philosophy by 