"The materialist theory of knowledge amounts, then, to this statement, that the human organ of cognition radiates no m…"

"One who knows little may explain that little with more ease and efficacy than one who has his head stuffed full of th…"

"Nothing can be learned without mental exertion. If you are concerned in your further development, you will recognize …"

"My logic deserves its proletarian qualification for the reason that it requires for its understanding the overcoming …"

"Logic aims to instruct the human mind as to its own nature and processes; it will lay bare the interior working of ou…"

"The human brain performs the function of thinking as involuntarily as the chest the function of breathing. However, w…"

"It is with logic as it is with other sciences. They draw wisdom from the mysterious source of plain experience. Agric…"

"Much of what I have to say for my case may sound wonderful, because it runs counter to the popular prejudice, but the…"

"It is a peculiarity of thought that it never stays with itself, but always digresses to other things."

"But it is not alone the harmony of music which has such a power over the mind. The harmony of colors, every art and s…"