If education is to develop human nature so that it may attain the object of its being, it must involve the exercise of judgment.

Freedom in the practical sense is the independence of the power of choice from necessitation by impulses of sensibility

The light dove, cleaving the air in her free flight, and feeling its resistance, might imagine that its flight would be still easier in empty space.

Freedom is that faculty that enlarges the usefulness of all other faculties.

Thoughts without content are empty, intuitions without concepts are blind... The understanding can intuit nothing, the senses can think nothing. Only through their union can knowledge arise.

A science of all these possible kinds of space [the higher dimensional ones] would undoubtedly be the highest enterprise which a finite understanding could undertake in the field of geometry... If it is possible that there could be regions with other dimensions, it is very likely that God has somewhere brought them into being.

If I am to constrain you by any law, it must be one by which I am also bound.