A reflexive pronoun is used as the object of a verb or preposition. It always refers to the subject of the sentence.
He made himself famous by pursuing what seemed to be a new discovery.
He found himself experimenting on a principle of light and sound.
He was very sure of himself and the importance of his discovery.
He worked on this principle all by himself.
A sentence will continue to express a complete thought even if the intensive pronoun is deleted from it.
The institute itself offered Doppler the professorship in practical geometry and elementary mathematics.
The institute offered Doppler the professorship in practical geometry and elementary mathematics.
However, a reflexive pronoun plays a vital role in completing the thought of a sentence and cannot be deleted.
Complete thought:
He made himself famous by pursuing a new discovery.
Incomplete thought:
He made famous by pursuing a new discovery.
Complete thought:
He worked on this principle all by himself.
Incomplete thought:
He worked on this principle all by.