You do not settle whether an argument is justified by merely showing that it is of some use. The distinction is not between useful and useless experiments but between barbarous and civilized behaviour. Vivisection is a social evil because if it advances human knowledge, it does so at the expense of human character.
There are black zones of shadow close to our daily paths, and now and then some evil soul breaks a passage through. When that happens, the man who knows must strike before reckoning the consequences.
When anything is in the presence of evil, but is not as yet evil, the presence of good arouses the desire of good in that thing; but the presence of evil, which makes a thing evil, takes away the desire and friendship of the good; for that which was once both good and evil has now become evil only, and the good has no friendship with evil.
What is wanted - whether this is admitted or not - is nothing less than a fundamental remolding, indeed weakening and abolition of the individual: one never tires of enumerating and indicating all that is evil and inimical, prodigal, costly, extravagant in the form individual existence has assumed hitherto, one hopes to manage more cheaply, more safely, more equitably, more uniformly if there exist only large bodies and their members.
An pretend and evil friend is haughty to be feared than a unmanageable beast; a unmanageable beast may mouthful your build up, but an evil friend fortitude mouthful your intellect.
Is there not in every human soul a primitive spark, a divine element, incorruptible in this world and immortal in the next, which can be developed by goodness, kindled, lit up, and made to radiate, and which evil can never entirely extinguish.
For among other evils caused by being disarmed, it renders you contemptible; which is one of those disgraceful things which a prince must guard against.
There is nothing besides a spiritual world; what we call the world of the senses is the Evil in the spiritual world, and what we call Evil is only the necessity of a moment in our eternal evolution.