"All things excellent are as difficult as they are rare." (Ethics, Part V, Prop 42, Scholium)
"The medieval-Cartesian attempt to distinguish man from the rest of nature, to elevate him above the rest of the animal kingdom...(is) not only an illusory metaphysical extravagance, but also a symptom of a faulty psychology, whose moral consequences are serious..." (Ethics, Introduction)
"...In the animal world we find much that far surpasses human sagacity..." (Ethics, Part III, Prop 2, Scholium)
"Every individual thing...cannot exist or be determined to act unless it be determined to exist and to act by another cause which is also finite and has a determinate existence." (Ethics, Part I, Prop 28)
"Men are deceived in thinking themselves free, a belief that consists only in this, that they are conscious of their actions and ignorant of the causes of their actions." (Ethics, Part II, Prop 35, Scholium).