In the long run, nothing can withstand reason and experience, and the contradiction religion offers to both is palpable.

The ego represents what we call reason and sanity, in contrast to the id which contains the passions.

Tobacco is the only excuse for Columbus's misadventure in discovering America.

The assumption that everything past is preserved holds good even in mental life only on condition that the organ of the mind has remained intact and that its tissues have not been damaged by trauma or inflammation. But destructive influences which can be compared to causes of illness like these are never lacking in the history of a city, even if it has had a less chequered past than Rome, and even if, like London, it has hardly ever suffered from the visitations of an enemy.

Religious illusion must bow to scientific truth. It is in total error about the nature of the true world. Only science is not an illusion.

Taboo restrictions are distinct from religious or moral prohibitions. They are not based upon any divine ordinance, but may be said to impose themselves on their own account. They differ from moral prohibitions in that they fall into no system that declares quite generally that certain abstinences must be observed and gives reasons for that necessity.

So in every individual the two trends, one towards personal happiness and the other unity with the rest of humanity, must contend with each other.