Georg Wilhelm Friedrich Hegel - Science of Logic
"A plastic discourse requires a plasticity of sense also in hearing and understanding; but youths and men of such a temper who would calmly suppress their own
reflections and opinions in which original thought
is so impatient to manifest itself, such listeners attentive to the facts as Plato portrayed them, could hardly be imagined in a modern dialogue; and even less could one count on readers of similar disposition. On the contrary, all too often and all too vehemently have I been confronted by opponents incapable of the simple consideration that their opinions and objections imply categories which are presuppositions and themselves in need of being criticized first before they are put to use. Lack of selfawareness in this matter is incredibly profound; it is responsible for the misunderstanding which is the cause of all others, the nasty and uneducated practice of taking for a category under consideration something other
than this category itself."
The text was taken from Preface to the second edition.