There is no possible line of conduct which has at some time and place been condemned, and which has not at some other time and place been enjoined as a duty.

Passions weaken, but habits strengthen, with age, and it is the great task of youth to set the current of habit and to form the tastes which are most productive of happiness in life.

The period of Catholic ascendancy was on the whole one of the most deplorable in the history of the human mind. . . . The spirit that shrinks from enquiry as sinful and deems a state of doubt a state of guilt, is the most enduring disease that can afflict the mind of man. Not till the education of Europe passed from the monasteries to the universities, not till Mohammedan science, and classical free thought, and industrial independence broke the sceptre of the Church, did the intellectual revival of Europe begin.

In proportion to its power, Protestantism has been as persecuting as Catholicism.

Spain and southern Italy, in which Catholicism has most deeply implanted its roots, are even now, probably beyond all other countries in Europe, those in which inhumanity to animals is most wanton and unrebuked.

The moral duty to be expected in different ages is not a unity of standard, or of acts, but a unity of tendency ... At one time the benevolent affections embrace merely the family, soon the circle expanding includes first a class, then a nation, then a coalition of nations, then all humanity and finally, its influence is felt in the dealings of man with the animal world.

It had been boldly predicted by some of the early Christians that the conversion of the world would lead to the establishment of perpetual peace. In looking back, with our present experience, we are driven to the melancholy conclusion that, instead of diminishing the number of wars, ecclesiastical influence has actually and very seriously increased it.