I don't think the human mind can comprehend the past and the future. They are both just illusions that can manipulate you into thinking there's some kind of change.

Anything that seems to be set in stone or inalterable can, indeed, change. In matters both large and small, it holds true that every change begins in the mind.

The snake that cannot shed its skin perishes. As well the minds which are prevented from changing their opinions; they cease to be mind.

Change based on principle is progress. Constant change without principle becomes chaos.

A lot of people have pretty little heads, but it's difficult to find a pretty little mind.

But we must not stop with the cultivation of a tough mind. The gospel also demands a tender heart. ... What is more tragic than to see a person who has risen to the disciplined heights of toughmindedness but has at the same time sunk to the passionless depths of hardheartedness?