Since the imagination, therefore, in running from low to high, finds an opposition in its internal qualities and principles, and since the soul, when elevated with joy and courage, in a manner seeks opposition, and throws itself with alacrity into any scene of thought or action, where its courage meets with matter to nourish and employ it; it follows, that everything, which invigorates and inlivens the soul, whether by touching the passions or imagination naturally conveys to the fancy this inclination for ascent, and determines it to run against the natural stream of its thoughts and conceptions.