“It is not my mode of thought that has caused my misfortunes, but the mode of thought of others.”

“Time is but a mode of thought”

“A mode of thought does not become 'critical' simply by attributing that label to itself, but by virtue of its content.”

“No great improvements in the lot of mankind are possible until a great change takes place in the fundamental constitution of their modes of thought.”

“There is no mode of action, no form of emotion, that we do not share with the lower animals. It is only by language that we rise above them, or above each other - by language, which is the parent, and not the child, of thought.”

“It's hardly possible to overstate the value, in the present state of human improvement, of placing human beings in contact with other persons dissimilar to themselves, and with modes of thought and action unlike those with which they are familiar. Such communication has always been... one of the primary sources of progress. ”