Healthy discontent is the prelude to progress.

Healthy discontent is the prelude to progress.

Restlessness is discontent — and discontent is the first necessity of progress. Show me a thoroughly satisfied man — and I will show you a failure.

One can measure the greatness and the moral progress of a nation by looking at how it treats its animals

Honest disagreement is often a good sign of progress.

I abhor vivisection with my whole soul. All the scientific discoveries stained with innocent blood I count as of no consequence.