The discovery of truth is prevented more effectively, not by the false appearance things present and which mislead into error, not directly by weakness of the reasoning powers, but by preconceived opinion, by prejudice. Parerga and Paralipomena

Yet living and dying, honour and dishonour, pain and pleasure, riches and poverty, and so forth are equally the lot of good men and bad. Things like these neither elevate nor degrade; and therefore they are no more good than they are evil. Book II

When does the soul obtain truth?—for in attempting to consider anything in company with the body she is obviously deceived. ...Then must not existence be revealed to her in thought, if at all? ...And thought is best when the mind is gathered into herself and none of these things trouble her—neither sounds nor sights nor pain nor any pleasure—when she has as little as possible to do with the body, and has no bodily sense or feeling, but is aspiring after being? ...And in this the philosopher dishonors the body; his soul runs away from the body and desires to be alone and by herself? The Trials Of Socrates

“Man serves the interests of no creature except himself.” Animal Farm