Personally, People Know Themselves Very Poorly.

The Fact Is, Every Thinker, Every Philosopher, The Moment He Is Forced To Abandon His One-sided Intellectual Occupation By Practical Necessity, Immediately Returns To The General Point Of View Of Mankind.

Everyone Is Free To Set Up An Opinion And To Adduce Proofs In Support Of It. Whether, Though, A Scientist Shall Find It Worth His While To Enter Into Serious Investigations Of Opinions So Advanced Is A Question Which His Reason And Instinct Alone Can Decide. If These Things, In The End, Should Turn Out To Be True, I Shall Not Be Ashamed Of Being The Last To Believe Them.

The Presentations And Conceptions Of The Average Man Of The World Are Formed And Dominated, Not By The Full And Pure Desire For Knowledge As An End In Itself, But By The Struggle To Adapt Himself Favourably To The Conditions Of Life.

Ordinarily Pleasure And Pain Are Regarded As Different From Sensations.

What Mach Calls A Thought Experiment Is Of Course Not An Experiment At All. At Bottom It Is A Grammatical Investigation.