Answer:
This statement is true in the deontological ethical theory developed by Immanuel Kant (22 April 1724 – 12 February 1804).
Step-by-step explanation:
With this statement Kant meant that each person including yourself has a value and has to be treated with respect, but not as a means to an end. For example, Kylie takes a job in a new company. She can see that Jeff really likes her and can help her to get a promotion quickly. She treats him as a tool (means) to her goal to get a promotion (end).
Within Kantian ethical system it is wrong. Kylie should work towards promotion herself and never under expense of Jeff. She can accept help from him that would not ultimately hurt his own position.
Another example, of individual treating himself as a means to an end. Young member of Communist party in early USSR follows through every order though he knows that he will become a scapegoat in the end. He thinks that he has no value and is only an end of building Communism.