Without contraries is no progression. Attraction and repulsion, reason and energy, love and hate, are necessary to human existence. – William Blake
The man who never alters his opinion is like standing water, and breeds reptiles of the mind. – William Blake
To generalize is to be an idiot. To particularize is the alone distinction of merit. General knowledge are those knowledge that idiots possess. – William Blake
Nature in darkness groans and men are bound to sullen contemplation in the night: restless they turn on beds of sorrow; in their inmost brain feeling the crushing wheels, they rise, they write the bitter words of stern philosophy and knead the bread of knowledge with tears and groans. – William Blake
The beginning, middle, and end of the birth, growth, and perfection of whatever we behold is from contraries, by contraries, and to contraries; and whatever contrariety is, there is action and reaction, there is motion, diversity, multitude, and order, there are degrees, succession and vicissitude. – Giordano Bruno